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Line 1: {{task\|Basic language learning}}~~[[Category:String~~ ~~manipulation]][[Category: String manipulation]]{{basic data operation}}~~ {{basic data operation}} Create a string variable equal to any text value. Prepend the string variable with another string literal. If your language supports any idiomatic ways to do this without referring to the variable twice in one expression, include such solutions. [[Category:String manipulation]] [[Category: String manipulation]] [[Category:Simple]] {{omit from\|bc\|No string operations in bc}} {{omit from\|dc\|No string operations in dc}} ;Task: Create a string variable equal to any text value. Prepend the string variable with another string literal. If your language supports any idiomatic ways to do this without referring to the variable twice in one expression, include such solutions. To illustrate the operation, show the content of the variable. <br><br> =={{header\|11l}}== {{trans\|Python}} <syntaxhighlight lang="11l">V s = ‘12345678’ s = ‘0’s print(s)</syntaxhighlight> {{out}} <pre> 012345678 </pre> =={{header\|360 Assembly}}== <syntaxhighlight lang="360asm">* String prepend - 14/04/2020 PREPEND CSECT USING PREPEND,13 base register B 72(15) skip savearea DC 17F'0' savearea SAVE (14,12) save previous context ST 13,4(15) link backward ST 15,8(13) link forward LR 13,15 set addressability MVC C+L'B(L'A),A c=a MVC C(L'B),B c=b+c (prepend) XPRNT C,L'C print buffer L 13,4(0,13) restore previous savearea pointer RETURN (14,12),RC=0 restore registers from calling sav A DC C'world!' a B DC C'Hello ' b C DC CL80' ' c END PREPEND</syntaxhighlight> {{out}} <pre> Hello world! </pre> =={{header\|AArch64 Assembly}}== {{works with\|as\|Raspberry Pi 3B version Buster 64 bits}} <syntaxhighlight lang="aarch64 assembly"> /* ARM assembly AARCH64 Raspberry PI 3B / / program appendstr64.s / /*****************************************/ / Constantes file / /*****************************************/ / for this file see task include a file in language AArch64 assembly/ .include "../includeConstantesARM64.inc" /*****************************************/ / Initialized data / /****************************************/ .data szMessString: .asciz "British Museum.\n" szComplement: .skip 80 szStringStart: .asciz "The rosetta stone is at " szCarriageReturn: .asciz "\n" /****************************************/ / UnInitialized data / /****************************************/ .bss /****************************************/ / code section / /****************************************/ .text .global main main: ldr x0,qAdrszMessString // display message bl affichageMess ldr x0,qAdrszMessString ldr x1,qAdrszStringStart bl prepend // append sting2 to string1 ldr x0,qAdrszMessString bl affichageMess ldr x0,qAdrszCarriageReturn bl affichageMess 100: // standard end of the program mov x0,0 // return code mov x8,EXIT // request to exit program svc 0 // perform system call qAdrszMessString: .quad szMessString qAdrszStringStart: .quad szStringStart qAdrszCarriageReturn: .quad szCarriageReturn /***********************************************/ / append two strings / /************************************************/ / x0 contains the address of the string1 / / x1 contains the address of the string2 / prepend: stp x1,lr,[sp,-16]! // save registers mov x3,#0 // length counter 1: // compute length of string 1 ldrb w4,[x0,x3] cmp w4,#0 cinc x3,x3,ne // increment to one if not equal bne 1b // loop if not equal mov x5,#0 // length counter insertion string 2: // compute length of insertion string ldrb w4,[x1,x5] cmp x4,#0 cinc x5,x5,ne // increment to one if not equal bne 2b cmp x5,#0 beq 99f // string empty -> error add x3,x3,x5 // add 2 length add x3,x3,#1 // +1 for final zero mov x6,x0 // save address string 1 mov x0,#0 // allocation place heap mov x8,BRK // call system 'brk' svc #0 mov x5,x0 // save address heap for output string add x0,x0,x3 // reservation place x3 length mov x8,BRK // call system 'brk' svc #0 cmp x0,#-1 // allocation error beq 99f mov x4,#0 // counter byte string 2 3: ldrb w3,[x1,x4] // load byte string 2 cbz x3,4f // zero final ? strb w3,[x5,x4] // store byte string 2 in heap add x4,x4,1 // increment counter 1 b 3b // no -> loop 4: mov x2,#0 // counter byte string 1 5: ldrb w3,[x6,x2] // load byte string 1 strb w3,[x5,x4] // store byte string in heap cbz x3,6f // zero final ? add x2,x2,1 // no -> increment counter 1 add x4,x4,1 // no -> increment counter 2 b 5b // no -> loop 6: // recopie heap in string 1 mov x2,#0 // counter byte string 7: ldrb w3,[x5,x2] // load byte string in heap strb w3,[x6,x2] // store byte string 1 cbz x3,100f // zero final ? add x2,x2,1 // no -> increment counter 1 b 7b // no -> loop 100: ldp x1,lr,[sp],16 // restaur 2 registers ret // return to address lr x30 /******************************************************/ / File Include fonctions / /******************************************************/ / for this file see task include a file in language AArch64 assembly / .include "../includeARM64.inc" </syntaxhighlight> {{Output}} <pre> British Museum. The rosetta stone is at British Museum. </pre> =={{header\|Action!}}== <syntaxhighlight lang="action!">PROC Append(CHAR ARRAY text,suffix) BYTE POINTER srcPtr,dstPtr BYTE len len=suffix(0) IF text(0)+len>255 THEN len=255-text(0) FI IF len THEN srcPtr=suffix+1 dstPtr=text+text(0)+1 MoveBlock(dstPtr,srcPtr,len) text(0)==+suffix(0) FI RETURN PROC Prepend(CHAR ARRAY text,prefix) CHAR ARRAY tmp(256) SCopy(tmp,text) SCopy(text,prefix) Append(text,tmp) RETURN PROC TestPrepend(CHAR ARRAY text,preffix) PrintF("Source ""%S"" at address %H%E",text,text) PrintF("Prepend ""%S""%E",preffix) Prepend(text,preffix) PrintF("Result ""%S"" at address %H%E",text,text) PutE() RETURN PROC Main() CHAR ARRAY text(256) text(0)=0 TestPrepend(text,"World!") TestPrepend(text,"Hello ") RETURN</syntaxhighlight> {{out}} [https://gitlab.com/amarok8bit/action-rosetta-code/-/raw/master/images/String_prepend.png Screenshot from Atari 8-bit computer] <pre> Source "" at address $2A8A Prepend "World!" Result "World!" at address $2A8A Source "World!" at address $2A8A Prepend "Hello " Result "Hello World!" at address $2A8A </pre> =={{header\|Ada}}== In Ada, a variable of type String cannot change its length. So the variable S which we will change, need to be of the type Unbounded_String. Thus the need for conversions from String literal to Unbounded_String for initialization, and from Unbounded_String to String for printing. <syntaxhighlight lang="ada">with Ada.Text_IO; with Ada.Strings.Unbounded; use Ada.Strings.Unbounded; procedure Prepend_String is S: Unbounded_String := To_Unbounded_String("World!"); begin S := "Hello " & S;-- this is the operation to prepend "Hello " to S. Ada.Text_IO.Put_Line(To_String(S)); end Prepend_String;</syntaxhighlight> {{out}} <pre>Hello World!</pre> =={{header\|ALGOL 68}}== {{works with\|ALGOL 68\|Revision 1.}} {{works with\|ALGOL 68G\|Any - tested with release [http://sourceforge.net/projects/algol68/files/algol68g/algol68g-2.7 algol68g-2.7].}} {{works with\|ELLA ALGOL 68\|Any (with appropriate job cards).}} '''File: String_prepend.a68'''<~~lang~~syntaxhighlight lang="algol68">#!/usr/bin/a68g --script # # -- coding: utf-8 -- # STRING str := "12345678"; "0" +=: str; print(str)</~~lang~~syntaxhighlight>~~'''Output:'''~~ {{out}} <pre> 012345678 </pre> =={{header\|AppleScript}}== AppleScript text is immutable, so prepending is only possible by creating a new text through concatenation of the variable's existing contents to the other string: <syntaxhighlight lang="applescript">set aVariable to "world!" set aVariable to "Hello " & aVariable return aVariable</syntaxhighlight> {{output}} <syntaxhighlight lang="applescript">"Hello world!"</syntaxhighlight> It's a similar situation with NSString class in AppleScriptObjC. This has various ways of achieving the same thing, probably the most sensible of which is the first of the following: <syntaxhighlight lang="applescript">use AppleScript version "2.4" -- OS X 10.10 (Yosemite) or later use framework "Foundation" set aVariable to current application's class "NSString"'s stringWithString:("world!") set aVariable to aVariable's stringByReplacingCharactersInRange:({0, 0}) withString:("Hello ") -- return aVariable as text -- Or: set aVariable to current application's class "NSString"'s stringWithString:("world!") set aVariable to current application's class "NSString"'s stringWithFormat_("%@%@", "Hello ", aVariable) -- return aVariable as text -- Or: set aVariable to current application's class "NSString"'s stringWithString:("world!") set aVariable to aVariable's stringByReplacingOccurrencesOfString:("^") withString:("Hello ") ¬ options:(current application's NSRegularExpressionSearch) range:({0, 0}) -- return aVariable as text</syntaxhighlight> But there's also an NS''Mutable''String class. This has 'replace' versions of the 'stringByReplacing' methods above and also this <tt>insertString:atIndex:</tt> method: <syntaxhighlight lang="applescript">use AppleScript version "2.4" -- OS X 10.10 (Yosemite) or later use framework "Foundation" set aVariable to current application's class "NSMutableString"'s stringWithString:("world!") tell aVariable to insertString:("Hello ") atIndex:(0) return aVariable as text</syntaxhighlight> {{output}} <syntaxhighlight lang="applescript">"Hello world!"</syntaxhighlight> =={{header\|Arturo}}== <syntaxhighlight lang="rebol">a: "World" a: "Hello" ++ a print a b: "World" b: append "Hello" b print a c: "World" prefix 'c "Hello" print c d: "World" print prefix d "Hello"</syntaxhighlight> {{out}} <pre>HelloWorld HelloWorld HelloWorld HelloWorld</pre> =={{header\|Asymptote}}== <syntaxhighlight lang="asymptote">string s1 = " World!"; write("Hello" + s1); write("Hello", s1); string s2 = "Hello" + s1; write(s2);</syntaxhighlight> =={{header\|AutoHotkey}}== <~~lang~~syntaxhighlight lang="autohotkey">s := "foo" s := s "bar" Msgbox % s</~~lang~~syntaxhighlight> {{out}} ~~'''output:'''~~ <pre> foobar Line 28 ⟶ 344: =={{header\|AWK}}== <syntaxhighlight lang="awk"> ~~<lang AWK>~~ # syntax: GAWK -f STRING_PREPEND.AWK BEGIN { Line 36 ⟶ 352: exit(0) } </syntaxhighlight> ~~</lang>~~ {{out}} ~~<p>output:</p>~~ <pre> foobar </pre> =={{header\|BaCon}}== <syntaxhighlight lang="bacon">s$ = "prepend" s$ = "String " & s$ PRINT s$</syntaxhighlight> {{out}} <pre>String prepend</pre> =={{header\|BASIC}}== <~~lang~~syntaxhighlight ~~BBC~~lang="bbc ~~BASIC~~basic">S$ = " World!" S$ = "Hello" + S$ PRINT S$ </syntaxhighlight> ~~</lang>~~ {{out}} <pre>Hello World!</pre> ==={{header\|Applesoft BASIC}}=== <syntaxhighlight lang="applesoft basic">100 LET S$=" World!" 110 LET S$="Hello"+S$ 120 PRINT S$</syntaxhighlight> ==={{header\|BASIC256}}=== <syntaxhighlight lang="basic256">a$ = " World!" a$ = "Hello"; a$ print a$ # would also be valid a$ = "Hello" + a$ # and a$ = "Hello" & a$</syntaxhighlight> ==={{header\|Chipmunk Basic}}=== {{works with\|Chipmunk Basic\|3.6.4}} {{works with\|Applesoft BASIC}} {{works with\|BASICA}} {{works with\|GW-BASIC}} {{works with\|QBasic}} {{works with\|MSX BASIC}} <syntaxhighlight lang="qbasic">10 A$ = " World!" 20 A$ = "Hello" + A$ 30 PRINT A$</syntaxhighlight> ==={{header\|GW-BASIC}}=== {{works with\|PC-BASIC\|any}} {{works with\|Applesoft BASIC}} {{works with\|BASICA}} {{works with\|Chipmunk Basic}} {{works with\|QBasic}} {{works with\|MSX BASIC}} <syntaxhighlight lang="qbasic">10 A$ = " World!" 20 A$ = "Hello" + A$ 30 PRINT A$</syntaxhighlight> ==={{header\|IS-BASIC}}=== <syntaxhighlight lang="is-basic">100 LET S$=" World!" 110 LET S$="Hello"&S$ 120 PRINT S$</syntaxhighlight> ==={{header\|MSX Basic}}=== {{works with\|MSX BASIC\|any}} {{works with\|Applesoft BASIC}} {{works with\|BASICA}} {{works with\|Chipmunk Basic}} {{works with\|QBasic}} <syntaxhighlight lang="qbasic">10 A$ = " World!" 20 A$ = "Hello" + A$ 30 PRINT A$</syntaxhighlight> ==={{header\|Run BASIC}}=== {{works with\|BASIC256}} {{works with\|Liberty BASIC}} {{works with\|QB64}} {{works with\|QBasic}} {{works with\|Yabasic}} <syntaxhighlight lang="runbasic">a$ = " World!" a$ = "Hello" + a$ print a$ ' en RB, LB and BASIC256 would also be valid a$ = "Hello"; a$</syntaxhighlight> ==={{header\|Quite BASIC}}=== {{works with\|BASICA}} {{works with\|Chipmunk Basic}} {{works with\|GW-BASIC}} {{works with\|MSX BASIC}} {{works with\|QBasic}} <syntaxhighlight lang="qbasic">10 LET A$ = " World!" 20 LET A$ = "Hello" + A$ 30 PRINT A$</syntaxhighlight> ==={{header\|True BASIC}}=== {{works with\|BASIC256}} <syntaxhighlight lang="qbasic">LET a$ = " World!" LET a$ = "Hello" & a$ PRINT a$ END</syntaxhighlight> ==={{header\|Yabasic}}=== {{works with\|BASIC256}} {{works with\|Liberty BASIC}} {{works with\|QB64}} {{works with\|QBasic}} {{works with\|Run BASIC}} <syntaxhighlight lang="freebasic">a$ = " World!" a$ = "Hello" + a$ print a$</syntaxhighlight> ==={{header\|~~BBC~~Binary ~~BASIC~~Lambda Calculus}}=== BLC program ~~{{works with\|BBC BASIC}}~~ <pre>18 16 46 80 05 bc bc fd f6 e0 67 6d 61</pre> based on https://github.com/tromp/AIT/blob/master/rosetta/catstrings.lam prepends "ma" to "gma" to output "magma". =={{header\|Bracmat}}== <~~lang~~syntaxhighlight lang="bracmat"> World!:?string & str$("Hello " !string):?string & out$!string</~~lang~~syntaxhighlight> <pre>Hello World!</pre> =={{header\|C}}== <syntaxhighlight lang="c">#include<stdio.h> #include<string.h> #include<stdlib.h> int main() { char str[100]="my String"; char cstr="Changed "; char dup; sprintf(str,"%s%s",cstr,(dup=strdup(str))); free(dup); printf("%s\n",str); return 0; }</syntaxhighlight> {{out}} <pre>Changed my String</pre> =={{header\|C sharp}}== <syntaxhighlight lang="csharp">using System; namespace PrependString { class Program { static void Main(string[] args) { string str = "World"; str = "Hello " + str; Console.WriteLine(str); Console.ReadKey(); } } }</syntaxhighlight> <pre>Hello World</pre> =={{header\|C++}}== <~~lang~~syntaxhighlight lang="cpp">include <vector> #include <algorithm> #include <string> Line 75 ⟶ 527: std::cout << prepended << std::endl ; return 0 ; }</~~lang~~syntaxhighlight> {{out}} <pre>prepended tomy string</pre> =={{header\|Clojure}}== ===A pure function implementation with immutability === <syntaxhighlight lang="clojure"> (defn str-prepend [a-string, to-prepend] (str to-prepend a-string)) </syntaxhighlight> === REPL demonstrations with mutability in mind === a) with the atom data structure <syntaxhighlight lang="clojure"> (def s (atom "World")) (swap! s #(str "Hello, " %)) user=> @s user=> "Hello, Wolrd" </syntaxhighlight> b) with the ref data structure <syntaxhighlight lang="clojure"> (def s (ref "World")) (dosync (alter s #(str "Hello " %))) user=> @s user=> "Hello World" </syntaxhighlight> =={{header\|COBOL}}== <syntaxhighlight lang="cobol"> identification division. program-id. prepend. data division. working-storage section. 1 str pic x(30) value "World!". 1 binary. 2 len pic 9(4) value 0. 2 scratch pic 9(4) value 0. procedure division. begin. perform rev-sub-str move function reverse ("Hello ") to str (len + 1:) perform rev-sub-str display str stop run . rev-sub-str. move 0 to len scratch inspect function reverse (str) tallying scratch for leading spaces len for characters after space move function reverse (str (1:len)) to str . end program prepend.</syntaxhighlight> <pre>Hello World!</pre> {{works with\|GNU Cobol\|2.0}} <~~lang~~syntaxhighlight lang="cobol"> >>SOURCE FREE PROGRAM-ID. prepend. Line 92 ⟶ 598: DISPLAY str . END PROGRAM prepend.</~~lang~~syntaxhighlight> =={{header\|ColdFusion}}== === Classic tag based CFML === <syntaxhighlight lang="cfm"> <cfoutput> <cfset who = "World!"> #"Hello " & who# </cfoutput> </syntaxhighlight> {{Output}} <pre> Hello World! </pre> === Script Based CFML === <syntaxhighlight lang="cfm"><cfscript> who = "World!"; greeting = "Hello " & who; writeOutput( greeting ); </cfscript></syntaxhighlight> {{Output}} <pre> Hello World! </pre> =={{header\|Common Lisp}}== A macro is necessary in order to prepend a string in-place: <~~lang~~syntaxhighlight lang="lisp">(defmacro prependf (s &rest strs) "Prepend the given string variable with additional strings. The string variable is modified in-place." `(setf ,s (concatenate 'string ,@strs ,s))) Line 102 ⟶ 632: (defvar str* "foo") (prependf str "bar") (format T "~a~%" str)</~~lang~~syntaxhighlight> {{out}} ~~Output:~~ <pre>barfoo</pre> =={{header\|D}}== <~~lang~~syntaxhighlight lang="d">import std.stdio; void main() { Line 113 ⟶ 643: s = "Hello " ~ s; writeln(s); }</~~lang~~syntaxhighlight> {{out}} <pre>Hello world!</pre> =={{header\|Delphi}}== {{libheader\| System.SysUtils}} <syntaxhighlight lang="delphi"> program String_preappend; {$APPTYPE CONSOLE} uses System.SysUtils; type TStringHelper = record helper for string procedure Preappend(str: string); end; { TStringHelper } procedure TStringHelper.Preappend(str: string); begin Self := str + self; end; begin var h: string; // with + operator h := 'World'; h := 'Hello ' + h; writeln(h); // with a function concat h := 'World'; h := concat('Hello ', h); writeln(h); // with helper h := 'World'; h.Preappend('Hello '); writeln(h); readln; end.</syntaxhighlight> {{out}} <pre>Hello World Hello World Hello World</pre> =={{header\|Dyalect}}== <syntaxhighlight lang="dyalect">var s = "world!" s = "Hello " + s print(s)</syntaxhighlight> =={{header\|Déjà Vu}}== <~~lang~~syntaxhighlight lang="dejavu">local :s "world!" set :s concat( "Hello " s) !print s</~~lang~~syntaxhighlight> {{out}} <pre>Hello world!</pre> =={{header\|EasyLang}}== <syntaxhighlight lang="easylang"> string$ = "Lang" string$ = "Easy" & string$ print string$ </syntaxhighlight> {{out}} <pre>EasyLang</pre> =={{header\|EchoLisp}}== <syntaxhighlight lang="scheme"> define-syntax-rule (set!-string-prepend a before) (set! a (string-append before a))) → #syntax:set!-string-prepend (define name "Presley") → name (set!-string-prepend name "Elvis ") name → "Elvis Presley" </syntaxhighlight> =={{header\|Elena}}== ELENA 6.x: <syntaxhighlight lang="elena">import extensions; import extensions'text; public program() { var s := "World"; s := "Hello " + s; console.writeLine(s); // Alternative way var s2 := StringWriter.load("World"); s2.insert(0, "Hello "); console.writeLine(s2); console.readChar() }</syntaxhighlight> =={{header\|Elixir}}== <syntaxhighlight lang="elixir"> str1 = "World!" str = "Hello, " <> str1 </syntaxhighlight> {{out}} "Hello, World!" =={{header\|Emacs Lisp}}== While strings in Emacs Lisp are mutable, they're fixed size. Therefore the <code>concat</code> function creates a new string and the existing string must be referenced twice: <syntaxhighlight lang="lisp">(defvar str "bar") (setq str (concat "foo" str)) str ;=> "foobar"</syntaxhighlight> This can be hidden by using a macro such as <code>cl-callf2</code> which expands into the above code: {{libheader\|cl-lib}} <syntaxhighlight lang="lisp">(require 'cl-lib) (defvar str "bar") (cl-callf2 concat "foo" str) str ;=> "foobar"</syntaxhighlight> Buffers can be thought of as expandable strings: <syntaxhighlight lang="lisp">(let ((buf (get-buffer-create "foo"))) (with-current-buffer buf (insert "bar")) (with-current-buffer buf (goto-char (point-min)) (insert "foo") (buffer-string))) ;; => "foobar"</syntaxhighlight> =={{header\|EMal}}== <syntaxhighlight lang="emal"> text greeting = "world" ^\|basic concatenation\|^ writeLine("hello " + greeting) ^\|changing the text in place\|^ writeLine(greeting.insert(0, "hello ")) writeLine(greeting) </syntaxhighlight> {{out}} <pre> hello world hello world hello world </pre> =={{header\|Erlang}}== Line 132 ⟶ 807: "Hello world" </pre> =={{header\|ERRE}}== <syntaxhighlight lang="erre"> ...... S$=" World!" S$="Hello"+S$ PRINT(S$) ...... </syntaxhighlight> {{out}} <pre>Hello World!</pre> =={{header\|F Sharp\|F#}}== <~~lang~~syntaxhighlight lang="fsharp">let mutable s = "world!" s <- "Hello, " + s printfn "%s" s</~~lang~~syntaxhighlight> =={{header\|Factor}}== <syntaxhighlight lang="factor"> "world" "Hello " prepend </syntaxhighlight> =={{header\|Falcon}}== '''VBA/Python programmer's approach not sure if it's the most falconic way''' <syntaxhighlight lang="falcon"> /* created by Aykayayciti Earl Lamont Montgomery April 9th, 2018 / s = "fun " s = s + "Falcon" > s </syntaxhighlight> {{out}} <pre> fun Falcon [Finished in 0.2s] </pre> =={{header\|Forth}}== Forth has no string prepend word, but adding it is not difficult. This demonstration starts from the low level operations that Forth gives us and quickly builds a simple set of "WORDS" (sub-routines) that let us move strings from address to address. Strings are just an address on the data stack so we can reference them as many times as we need to. Our prepend word makes use of the Return stack as a temporary storage for the address of the string we want to prepend. Standard Forth also provides a named general purpose buffer called PAD, so we make use of that too. With this PREPEND becomes part of the language. <syntaxhighlight lang="text">\ the following functions are commonly native to a Forth system. Shown for completeness : C+! ( n addr -- ) dup c@ rot + swap c! ; \ primitive: increment a byte at addr by n : +PLACE ( addr1 length addr2 -- ) \ Append addr1 length to addr2 2dup 2>r count + swap move 2r> c+! ; : PLACE ( addr1 len addr2 -- ) \ addr1 and length, placed at addr2 as counted string 2dup 2>r 1+ swap move 2r> c! ; \ Example begins here : PREPEND ( addr len addr2 -- addr2) >R \ push addr2 to return stack PAD PLACE \ place the 1st string in PAD R@ count PAD +PLACE \ append PAD with addr2 string PAD count R@ PLACE \ move the whole thing back into addr2 R> ; \ leave a copy of addr2 on the data stack : writeln ( addr -- ) cr count type ; \ syntax sugar for testing</syntaxhighlight> Test our language extensions interactively at the console <pre>256 buffer: string1 ok s" needs no introduction!" string1 place ok string1 writeln needs no introduction! ok s" This string " string1 prepend writeln This string needs no introduction! ok</pre> =={{header\|Fortran}}== ===Early inability=== Early Fortran had almost no ability to manipulate text except via overwriting text literals in a FORMAT statement used in a READ, that would then appear when the same FORMAT statement was used in a WRITE (!) perhaps as a heading. ===Initial difficulty=== With Fortran IV came the ability to use arrays of integers and the A1 format code in READ and WRITE statements for them. With sixteen-bit integers, one might use A2 and so forth, but the numerical values of the integers would not be convenient especially if the sign bit was involved. This would be even more difficult with floating-point variables. Still, the desire for good headings and annotations and flexible layout flogged one onwards. Following the Pascal "Hello world!" example, one might proceed somewhat as follows:<syntaxhighlight lang="fortran"> INTEGER4 I,TEXT(66) DATA TEXT(1),TEXT(2),TEXT(3)/"Wo","rl","d!"/ WRITE (6,1) (TEXT(I), I = 1,3) 1 FORMAT ("Hello ",66A2) DO 2 I = 1,3 2 TEXT(I + 3) = TEXT(I) TEXT(1) = "He" TEXT(2) = "ll" TEXT(3) = "o " WRITE (6,3) (TEXT(I), I = 1,6) 3 FORMAT (66A2) END</syntaxhighlight> This old-style source is acceptable to the F90 compiler as it stands. By chance, two characters per integer fits nicely but in many cases having one character per variable is easier for manipulation. So, as usual with Fortran, it's all done with arrays. The DATA statement demonstrates that a quoted string is acceptable as a value for an integer; it is just a matter of bit patterns, and this type miscegnation will work with floating-point variables also though resulting in even stranger numerical values. Looking more closely, note that an INTEGER4 variable can hold four eight-bit characters but only two-character text literals have been specified. Unlike integer constants, which might be considered to have leading zero digits, text literals are deemed to have trailing spaces as needed: <code>"Wo"</code> is deemed to be <code>"Wo "</code> to make up to the recipient's capacity for four characters, and when format code A2 is specified, the leftmost two characters in the variable are taken. The strange ideas of "little-endianism" have never flourished on mainframes! Thus, if the format code were to be A4, then "Wo " would appear, not " Wo". The first output (to standard output: unit 6) thus prepends the text "Hello " via the workings of the nominated FORMAT statement without a further mention of variable TEXT, itself not being modified in this action. Thus, this is an example of a single-mention possibility. Some versions of Fortran offered the ability to write to a variable such as an array rather than to a nominated output unit, via a statement like <code>WRITE (TEXT,1) (TEXT(I),I = 1,3)</code>, which array could then itself be written to the actual output via normal statements. This would involve a working variable within the routines for formatted I/O to hold the output, and thus provides one of the reasons that Fortran I/O implementations seldom enable re-entrancy - as with a WRITE statement whose output expression list includes a function evaluation, which function itself attempts to WRITE something, say to a log file, with both WRITE statements employing formatting statements. More modern compilers now require the recipient for this sort of WRITE statement to be of type CHARACTER, so the older style is blocked - and re-entrancy is still a problem. Still another variant involved writing to unit number zero, which did not actually send anything to an output recipient. Instead, the scratchpad used by the formatted I/O system would retain whatever was produced, which could then be read back via unit number zero. Indeed, reading from unit zero would reveal whatever had been the last line of the previous I/O statement. This would be of interest if a format error had been reported on a READ during some mass data acquisition, so that the error message could show the problematic input that had been obtained rather than just complain. But this facility was not common, and did not become a part of the F90 standard. Perhaps a BACKSPACE and re-read to a text variable will work instead... Retreating from FORMAT usage to the case of manipulating a "string" variable so as to prepend a given text to the working variable, first the existing content must be moved right to make room (again, an even number of characters is involved) which is achieved via the DO-loop, using certain constants. If on the other hand, text were to be removed from the front, then a loop would be needed to shift the surviving content leftwards. In doing this, one must pay attention to any overlaps and the direction of the loop! By chance, this exercise starts the placement after the end of the existing text but if instead the shift were to be two units, then the first-placed unit would land atop the tail end of the existing text. Thus, for rightwards shifts, one should start with the end of the surviving text and work back to its start. Having made space, the next statements merely assign some bit patterns to elements of TEXT, and then the result is revealed, again using known constants instead of the associated variables of the more general approach. The result from the two WRITE statements is of course <pre>Hello world! Hello world!</pre> ===Character facility=== With F77 came the CHARACTER type... <syntaxhighlight lang="fortran"> CHARACTER66 TEXT TEXT = "World!" TEXT = "Hello "//TEXT WRITE (6,) TEXT END </syntaxhighlight> This means that variable TEXT has space for 66 characters, addressed as TEXT(''first'':''last'') starting with one. There is no associated string length facility, so the first assignment places the six characters of the supplied literal, followed by spaces all the way to the end of TEXT. Alternatively, <code>TEXT(1:6) = "World!"</code> would place only six characters, leaving the rest of TEXT to hold whatever it may. This would probably be unsuitable for the next statement, which prepends "Hello " to the content of TEXT (including positions past six) and assigns the result to TEXT, overwriting its previous content - with the aid of a temporary working area. Although in principle there could be cunning schemes that update the recipient "in place" with a minimum of character copying to and fro, this doesn't happen. Only characters up to the capacity of the recipient will be transferred from the expression's result, and if the result is shorter than the capacity of the recipient, trailing spaces will be added. All of this is extra effort! And when TEXT is written out, all 66 characters will be sent forth. It is useful to have a function that locates the last non-blank character! ===Modern=== With F90, and standardised in F2003, came extensions that enable a variable to be "cut-to-fit" on each usage. The first assignment would discard any storage associated with TEXT and re-assign space matching the size of the expression's result, so TEXT would have six characters. In the next statement, the expression would be evaluated and produce twelve characters (six from "Hello ", and the six of the current size of TEXT), then the current storage for text would be discarded and TEXT re-allocated to be of size twelve. At some cost in overhead. On the other hand, rather than copy the result of an expression from the scratchpad to the recipient, with re-allocation, the recipient variable could be repointed to the result area: no copying needed. =={{header\|FreeBASIC}}== <syntaxhighlight lang="freebasic">' FB 1.05.0 Win64 Var s = "prepend" s = "String " + s Print s Sleep</syntaxhighlight> {{out}} <pre> String prepend </pre> =={{header\|Free Pascal}}== Free Pascal supports everything shown in [[#Pascal\|§ Pascal]] (except the <tt>string</tt> schema data type, <tt>string(20)</tt> must be written like here). Furthermore, using the compiler directive <tt>{$COperators}</tt> the following is possible, too: <syntaxhighlight lang="delphi">var line: string[20]; begin line := 'Hello '; {$COperators on} line += 'world!'; writeLn(line) end.</syntaxhighlight> =={{header\|FutureBasic}}== <syntaxhighlight lang="futurebasic"> include "NSLog.incl" void local fn DoIt CFStringRef s = @"world!" s = fn StringByAppendingString( @"Hello ", s ) NSLog(@"%@",s) end fn fn DoIt HandleEvents </syntaxhighlight> {{out}} <pre> Hello world! </pre> =={{header\|Gambas}}== '''[https://gambas-playground.proko.eu/?gist=cd5ab867c22e872d69ed81fd9da96707 Click this link to run this code]''' <syntaxhighlight lang="gambas">Public Sub Main() Dim sString1 As String = "world!" Dim sString2 As String = "Hello " sString1 = sString2 & sString1 Print sString1 End</syntaxhighlight> Output: <pre> Hello world! </pre> =={{header\|Go}}== <syntaxhighlight lang="go">s := "world!" s = "Hello, " + s</syntaxhighlight> =={{header\|Haskell}}== <syntaxhighlight lang="haskell"> Prelude> let f = (++" World!") Prelude> f "Hello" </syntaxhighlight> {{out}} <pre>"Hello world!"</pre> =={{header\|Icon}} and {{header\|Unicon}}== <~~lang~~syntaxhighlight lang="unicon">s := "world!" s := "Hello, " \|\| s</~~lang~~syntaxhighlight> To demonstrate how this could be done with only one reference to the variable during the prepend: <syntaxhighlight lang="unicon">procedure main() s := ", world" s[1:1] \|\|:= "Hello" write(s) end</syntaxhighlight> {{out}} <pre>prompt$ unicon -s prepend.icn -x Hello, world</pre> Another take on it, using String Scanning: <syntaxhighlight lang="unicon">procedure main() (s := ", world") ?:= "Hello" \|\| tab(0) write(s) end</syntaxhighlight> {{out}} <pre>prompt$ unicon -s prepend.icn -x Hello, world</pre> =={{header\|J}}== <~~lang~~syntaxhighlight lang="j"> s=: 'value' s value s=: 'new ',s s new value</~~lang~~syntaxhighlight> =={{header\|Java}}== Java does not have a prepend method.<br /> ~~<lang java>public class Prepend {~~ The most logical way to prepend a string value is with basic concatenation. <syntaxhighlight lang="java"> ~~public static void main(String[] args) {~~ String sstring = "~~world!~~def"; string = "abc" + string; ~~System.out.println("Hello " + s);~~ </syntaxhighlight> } You could also use the ''String.concat'' method. ~~}</lang>~~ <syntaxhighlight lang="java"> String string = "def"; ~~Output:~~ string = "abc".concat(string); </syntaxhighlight> ~~<pre>Hello world!</pre>~~ You could use the ''StringBuilder'' class which provides an ''insert'' method. <syntaxhighlight lang="java"> StringBuilder string = new StringBuilder(); string.append("def"); string.insert(0, "abc"); </syntaxhighlight> Additionally, you could use the ''String.format'' or ''String.formatted'' methods. <syntaxhighlight lang="java"> String string = "def"; string = String.format("abc%s", string); </syntaxhighlight> <syntaxhighlight lang="java"> String string = "def"; string = "abc%s".formatted(string); </syntaxhighlight> All of these will produce the following output. <pre> abcdef </pre> =={{header\|Javascript}}== <~~lang~~syntaxhighlight lang="javascript">// No built-in prepend var s=", World" s = "Hello" + s print(s);</~~lang~~syntaxhighlight> =={{header\|jq}}== <syntaxhighlight lang="jq">"world!" as $s \| "Hello " + $s</syntaxhighlight> =={{header\|Julia}}== <~~lang~~syntaxhighlight lang="julia">s = "world!" s = "Hello " s</~~lang~~syntaxhighlight> =={{header\|K}}== <syntaxhighlight lang="k"> s: "world!" "world!" "Hello " , s "Hello world!" </syntaxhighlight> =={{header\|Kotlin}}== <syntaxhighlight lang="scala">// version 1.0.6 fun main(args: Array<String>) { var s = "Obama" s = "Barack " + s println(s) // It's also possible to use this standard library function // though this is not what it's really intended for var t = "Trump" t = t.prependIndent("Donald ") println(t) }</syntaxhighlight> {{out}} <pre> Barack Obama Donald Trump </pre> =={{header\|Lambdatalk}}== <syntaxhighlight lang="scheme"> {def str World} -> str Hello, {str} -> Hello, World </syntaxhighlight> =={{header\|Lasso}}== <~~lang~~syntaxhighlight ~~Lasso~~lang="lasso">local(x = ', World!') #x->merge(1,'Hello') #x // Hello, World!</~~lang~~syntaxhighlight> =={{header\|LFE}}== Using the concatenation operator: <syntaxhighlight lang="lisp"> > (set s "world") "world" > (++ "hello " s) "hello world" </syntaxhighlight> Using the concatenation function: <syntaxhighlight lang="lisp"> > (set s "world") "world" > (string:concat "hello " s) "hello world" </syntaxhighlight> =={{header\|Lingo}}== <syntaxhighlight lang="lingo">str = "world!" put "Hello " before str put str -- "Hello world!"</syntaxhighlight> =={{header\|LiveCode}}== The idiomatic way is to use "before"<syntaxhighlight lang="livecode">put "world" into x put "hello" before x put x // hello world</syntaxhighlight> =={{header\|Lua}}== By concatenation: <syntaxhighlight lang="lua"> s = "12345678" s = "0" .. s print(s)</syntaxhighlight> By string formatting: <syntaxhighlight lang="lua"> s = "12345678" s = string.format("%s%s", "0", s) print(s)</syntaxhighlight> By list joining: <syntaxhighlight lang="lua"> s = "12345678" s = table.concat({"0", s}) print(s)</syntaxhighlight> {{out}} of each solution: <pre> 012345678 </pre> =={{header\|M2000 Interpreter}}== <syntaxhighlight lang="m2000 interpreter"> Module PrependString { A$="Hello" A$+=" World" Print A$ } PrependString </syntaxhighlight> ~~=={{header\|Mathematica}}==~~ ~~<lang Mathematica>a = "any text value";~~ ~~a = "another string literal" <> a (* using concatenation (no built-in prepend) )</lang>~~ {{out}} <pre> ~~<pre>"another string literalany text value"</pre>~~ Hello World </pre> =={{header\|Maple}}== <syntaxhighlight lang="maple">l := " World"; m := cat("Hello", l); n := "Hello"\|\|l; o := `\|\|`("Hello", l);</syntaxhighlight> {{out}} <pre> " World" "Hello World" "Hello World" "Hello World" </pre> =={{header\|Mathematica}}/{{header\|Wolfram Language}}== <syntaxhighlight lang="mathematica">a = "any text value"; a = "another string literal" <> a ( using concatenation (no built-in prepend) )</syntaxhighlight> {{out}} <pre>"another string literalany text value"</pre> =={{header\|Mercury}}== <~~lang~~syntaxhighlight lang="mercury">:- module string_prepend. :- interface. :- import_module io. Line 197 ⟶ 1,224: main(!IO) :- S = "World!\n", io.write_string("Hello " ++ S, !IO).</~~lang~~syntaxhighlight> {{out}} <pre> Hello World! </pre> =={{header\|Nanoquery}}== Nanoquery has no idiomatic way to prepend one string to another. <syntaxhighlight lang="nanoquery">s1 = " a test" s1 = "this is" + s1 println s1</syntaxhighlight> {{out}} <pre>this is a test</pre> =={{header\|Neko}}== The plus operator, +, concatenates string data. Neko treats strings as mutable fixed length buffers, so some care would need to be taken when prepending variables to variables as there may be buffer sizing to take into consideration. For literals, this is not a concern, as the literals are placed in buffers of the proper size by the compiler. <syntaxhighlight lang="actionscript">/* <doc><p>String prepend in Neko</pre></doc> */ var str = ", world" str = "Hello" + str $print(str, "\n")</syntaxhighlight> {{out}} <pre>prompt$ nekoc string-prepend.neko prompt$ neko string-prepend.n Hello, world</pre> =={{header\|NetRexx}}== <~~lang~~syntaxhighlight ~~NetRexx~~lang="netrexx">s_ = 'world!' s_ = 'Hello, 's_ say s_</~~lang~~syntaxhighlight> {{out}} <pre> Hello, world! </pre> =={{header\|NewLISP}}== <syntaxhighlight lang="newlisp">(setq str "bar") (push "foo" str) (println str)</syntaxhighlight> =={{header\|Nim}}== <syntaxhighlight lang="nim"># Direct way. var str1, str2 = "12345678" str1 = "0" & str1 echo str1 # Using "insert". str2.insert("0") echo str2 </syntaxhighlight> {{out}} <pre>012345678 012345678</pre> =={{header\|Objeck}}== <syntaxhighlight lang="objeck">class Prepend { function : Main(args : String[]) ~ Nil { s := "world!"; "Hello {$s}"->PrintLine(); } }</syntaxhighlight> <pre> Hello World! </pre> =={{header\|OCaml}}== <syntaxhighlight lang="ocaml">let () = let s = ", world" in let s = "Hello" ^ s in print_endline s</syntaxhighlight> =={{header\|Oforth}}== <syntaxhighlight lang="oforth">" World" "Hello" swap + println</syntaxhighlight> {{out}} <pre> Hello World </pre> =={{header\|PARI/GP}}== Not supported in GP. <~~lang~~syntaxhighlight lang="parigp">s = "world!"; s = Str("Hello, ", s)</~~lang~~syntaxhighlight> {{out}} <pre>%1 = "Hello, world!"</pre> =={{header\|Pascal}}== ''See also [[#Free Pascal\|Free Pascal]]'' {{works with\|Extended Pascal}} <syntaxhighlight lang="pascal">program stringPrepend(output); ~~{{works with\|Free Pascal\|2.6.2}}~~ ~~<lang Pascal>program StringPrepend;~~ ~~{$mode objfpc}{$H+}~~ ~~uses~~ ~~{$IFDEF UNIX}{$IFDEF UseCThreads}~~ ~~cthreads,~~ ~~{$ENDIF}{$ENDIF}~~ ~~Classes~~ ~~{ you can add units after this };~~ var line: string(20); ~~s: String = ' World !';~~ begin s line := 'Hello ' ~~+ s~~; line := line + 'world!'; ~~WriteLn(S);~~ writeLn(line); ~~ReadLn;~~ ~~end.</lang>~~ line := 'Hello '; ~~Output:~~ writeStr(line, line, 'world!'); ~~<pre>Hello World !</pre>~~ writeLn(line) end.</syntaxhighlight> {{out}} <pre>Hello world! Hello world!</pre> =={{header\|Perl}}== <syntaxhighlight lang ="perl">~~my $str =~~use ~~'bar'~~strict; use warnings; ~~substr $str, 0, 0, 'Foo';~~ use feature ':all'; ~~print $str;</lang>~~ ~~{{out}}~~ ~~<pre>Foobar</pre>~~ # explicit concatentation ~~=={{header\|Perl 6}}==~~ $_ = 'bar'; ~~<lang perl6># explicit concatentation~~ $_ = '~~byte~~Foo' . $_; say; ~~$_ = 'kilo' ~ $_;~~ ~~.say;~~ ~~# interpolation as concatenation~~ ~~$_ = 'buck';~~ ~~$_ = "mega$_";~~ ~~.say;~~ # lvalue substr $_ = '~~bit~~bar'; substr~~-rw(~~ $_, 0,0) =0, '~~nano~~Foo'; .say; ~~# regex substitution~~ ~~$_ = 'fortnight';~~ ~~s[^] = 'micro';~~ ~~.say;~~ # interpolation as concatenation ~~# reversed append assignment~~ # (NOT safe if concatenate sigils) ~~$_ = 'cooper';~~ $_ ~~[R~]~~= '~~mini~~bar'; $_ = "Foo$_"; ~~.say;</lang>~~ say;</syntaxhighlight> {{out}} <pre>~~kilobyte~~ Foobar ~~megabuck~~ Foobar ~~nanobit~~ Foobar ~~microfortnight~~ ~~minicooper~~</pre> =={{header\|Phix}}== {{libheader\|Phix/basics}} <!--<syntaxhighlight lang="phix">--> <span style="color: #004080;">string</span> <span style="color: #000000;">s</span> <span style="color: #0000FF;">=</span> <span style="color: #008000;">"World"</span> <span style="color: #000000;">s</span> <span style="color: #0000FF;">=</span> <span style="color: #008000;">"Hello "</span><span style="color: #0000FF;">&</span><span style="color: #000000;">s</span> <!--</syntaxhighlight>--> <b>NB:</b> s = prepend(s,"Hello ") gives typecheck: s is {"Hello ",87'W',111'o',114'r',108'l',100'd'}, of length 6, rather than the "Hello World" of length 11 you probably wanted.<br>        - and likewise s = prepend("Hello ",s) is not only the wrong way round but dies with typecheck: s is {"World",72'H',101'e',108'l',108'l',111'o',32' '} (length 7). =={{header\|Phixmonti}}== <syntaxhighlight lang="Phixmonti">/# Rosetta Code problem: https://rosettacode.org/wiki/String_prepend by Galileo, 10/2022 #/ "Hello " var s s "world" chain var s s print</syntaxhighlight> =={{header\|Picat}}== As usual there are a couple ways of doing this. The most common is probable to use string concatenation (<code>++</code>), but <code>append/3</code> might be useful if backtracking is needed. <syntaxhighlight lang="picat">go => S = "123456789", println(S), S := "A" ++ S, println(S), % append append("B",S,T), S := T, println(S), % insert at position S := insert(S,1,'C'), % note: must be a char to keep it a proper string println(S), % insert many characters S := insert_all(S,1,"DE"), println(S), nl.</syntaxhighlight> {{out}} <pre>123456789 A123456789 BA123456789 CBA123456789 DECBA123456789</pre> =={{header\|PicoLisp}}== <~~lang~~syntaxhighlight lang="picolisp">(setq Str1 "12345678!") (setq Str1 (pack "0" Str1)) (println Str1)</~~lang~~syntaxhighlight> {{out}} <pre> Line 292 ⟶ 1,424: =={{header\|PL/I}}== <syntaxhighlight lang="pl/i"> ~~<lang PL/I>~~ Pre_Cat: procedure options (main); / 2 November 2013 / declare s character (100) varying; Line 299 ⟶ 1,431: put (s); end Pre_Cat; </syntaxhighlight> ~~</lang>~~ <pre> dust bowl </pre> =={{header\|PlainTeX}}== <syntaxhighlight lang="tex">\def\prepend#1#2{% #1=string #2=macro containing a string \def\tempstring{#1}% \expandafter\expandafter\expandafter \def\expandafter\expandafter\expandafter #2\expandafter\expandafter\expandafter {\expandafter\tempstring#2}% } \def\mystring{world!} \prepend{Hello }\mystring Result : \mystring \bye</syntaxhighlight> Here is an equivalent code with eTeX capabilities: <syntaxhighlight lang="tex">\def\prepend#1#2{% #1=string #2=macro containing a string \edef#2{\unexpanded{#1}\unexpanded\expandafter{#2}}% } \def\mystring{world!} \prepend{Hello }\mystring Result : \mystring \bye</syntaxhighlight> =={{header\|PowerShell}}== <syntaxhighlight lang="powershell"> $str = "World!" $str = "Hello, " + $str $str </syntaxhighlight> <pre>Hello, World!</pre> =={{header\|Prolog}}== {{works with\|SWI-Prolog}} In its admirable wisdom, Prolog is generally unfriendly to state mutations and destructive assignment. However, it is also very flexible. Using the traditional representation of strings as lists of character codes, and the non-logical predicate `setarg/3`, we can destructively set the head and tail of the list to achieve a mutation of the variable holding the string. I define an operator for the purpose: <syntaxhighlight lang="prolog"> :- op(200, xfx, user:(=+)). %% +Prepend =+ +Chars % % Will destructively update Chars % So that Chars = Prepend prefixed to Chars. % eazar001 in ##prolog helped refine this approach. [X\|Xs] =+ Chars :- append(Xs, Chars, Rest), nb_setarg(2, Chars, Rest), nb_setarg(1, Chars, X). </syntaxhighlight> Example of this abomination in action: <syntaxhighlight lang="prolog"> ?- Str = `World!`, `Hello, ` =+ Str. Str = "Hello, World!".</syntaxhighlight> Note: I can't imagine when I would want to do this in Prolog. =={{header\|PureBasic}}== <~~lang~~syntaxhighlight lang="purebasic">S$ = " World!" S$ = "Hello" + S$ If OpenConsole() Line 312 ⟶ 1,509: Print(#CRLF$ + #CRLF$ + "Press ENTER to exit"): Input() CloseConsole() EndIf</~~lang~~syntaxhighlight> {{out}} ~~Sample output:~~ <pre>Hello World!</pre> =={{header\|Python}}== '''File: ~~String_prepend~~string_prepend.py'''~~<lang python>#!/usr/bin/env python~~ ~~# -- coding: utf-8 -- #~~ <syntaxhighlight lang="python">#!/usr/bin/env python ~~str = "12345678";~~ # -- coding: utf-8 -- ~~str = "0" + str; # by concatination #~~ ~~print(str)</lang>'''Output:'''~~ s = "12345678" s = "0" + s # by concatenation print(s)</syntaxhighlight> {{out}} <pre> 012345678 </pre> =={{header\|QB64}}== <syntaxhighlight lang="qbasic">s$ = "prepend" s$ = "String " + s$ Print s$</syntaxhighlight> {{out}} <pre>String prepend</pre> =={{header\|Quackery}}== <syntaxhighlight lang="quackery">$ "with a rubber duck." $ "One is never alone " swap join echo$</syntaxhighlight> {{out}} <pre>One is never alone with a rubber duck.</pre> =={{header\|Racket}}== <~~lang~~syntaxhighlight lang="racket">;there is no built-in way to set! prepend in racket (define str "foo") (set! str (string-append "bar " str)) Line 340 ⟶ 1,559: (set-prepend! macrostr "foo") (displayln macrostr) </syntaxhighlight> ~~</lang>~~ {{out}} <pre>bar foo foo bar</pre> =={{header\|Raku}}== (formerly Perl 6) <syntaxhighlight lang="raku" line># explicit concatentation $_ = 'byte'; $_ = 'kilo' ~ $_; .say; # interpolation as concatenation $_ = 'buck'; $_ = "mega$_"; .say; # lvalue substr $_ = 'bit'; substr-rw($_,0,0) = 'nano'; .say; # regex substitution $_ = 'fortnight'; s[^] = 'micro'; .say; # reversed append assignment $_ = 'cooper'; $_ [R~]= 'mini'; .say;</syntaxhighlight> {{out}} <pre>kilobyte megabuck nanobit microfortnight minicooper</pre> =={{header\|Red}}== <syntaxhighlight lang="red">Red [] s: "world" insert s "hello " print s </syntaxhighlight> {{out}} <pre>hello world</pre> =={{header\|REXX}}== <~~lang~~syntaxhighlight lang="rexx">zz= 'llo world!' /~~────────────────~~─────────────── using literal abuttal. ────────────/ zz= 'he'zz /This won't work if the variable name ~~/────────────────~~is ~~this~~ ~~won't~~X ~~work~~ isor ~~the~~ ~~first~~B / ~~/──────────────── variable name is X or B /~~ ~~zz='llo world!'~~ ~~zz='he'zz~~ say zz ~~/──────────────── using literal concatenation. /~~ gg = "llo world!" /─────────────── using literal concatenation.──────/ ~~gg = "llo world!"~~ gg = 'he' \|\| gg say gg ~~/──────────────── using variable concatenation./~~ aString= 'llo world!' /─────────────── using variable concatenation.─────/ ~~aString = 'llo world!'~~ bString = "he" aString = bString \|\| aString say aString</~~lang~~syntaxhighlight> '''output''' <pre> Line 369 ⟶ 1,627: hello world! </pre> =={{header\|Ring}}== <syntaxhighlight lang="ring"> aString = "World!" bString = "Hello, " + aString see bString + nl </syntaxhighlight> =={{header\|RPL}}== In HP-48+ RPL versions, the <code>STO+</code> instruction can either append or prepend a string to a variable containing already a string. "def" '<span style="color:green">Z</span>' STO "abc" '<span style="color:green">Z</span>' STO+ <span style="color:green">Z</span> '''Output''' <span style="color:grey"> 1:</span> "abcdef" =={{header\|Ruby}}== There is a method for prepending a string, aptly named "prepend". <~~lang~~syntaxhighlight lang="ruby">str = "llo world" str.prepend("He") p str #=> "Hello world"</~~lang~~syntaxhighlight> =={{header\|Rust}}== <syntaxhighlight lang="rust"> let mut s = "World".to_string(); s.insert_str(0, "Hello "); println!("{}", s); </syntaxhighlight> =={{header\|Scala}}== Evaluation in Scala worksheet <~~lang~~syntaxhighlight lang="scala"> val s = "World" // Immutables are recommended //> s : String = World val f2 = () => ", " //Function assigned to variable //> f2 : () => String = <function0> val s1 = "Hello" + f2() + s //> s1 : String = Hello, World println(s1); //> Hello, World</~~lang~~syntaxhighlight> =={{header\|sed}}== There are no variables in ''sed'', just two distinct locations for storing a string: The "pattern space" and the "hold space". To prepend a string literal to the pattern space, the <code>s</code> command can be used: <syntaxhighlight lang="sed">s/^/String Literal/</syntaxhighlight> To prepend a string literal to the hold space, it needs to be exchanged with the pattern space, before and after the operation: <syntaxhighlight lang="sed">x s/^/String Literal/ x</syntaxhighlight> =={{header\|Seed7}}== <~~lang~~syntaxhighlight lang="seed7">$ include "seed7_05.s7i"; const proc: main is func Line 393 ⟶ 1,681: s := "Hello " & s; writeln(s); end func;</~~lang~~syntaxhighlight> {{out}} <pre> Hello world! </pre> =={{header\|Sidef}}== <syntaxhighlight lang="ruby">var str = 'llo!'; str.sub!(/^/, 'He'); say str;</syntaxhighlight> or <syntaxhighlight lang="ruby">var str = 'llo!'; str.prepend!('He'); say str;</syntaxhighlight> {{out}} <pre>Hello!</pre> =={{header\|SNOBOL4}}== <syntaxhighlight lang="snobol4"> s = ', World!' OUTPUT = s = 'Hello' s END</syntaxhighlight> {{out}} <pre> Hello, World! </pre> =={{header\|SparForte}}== As a structured script. <syntaxhighlight lang="ada">#!/usr/local/bin/spar pragma annotate( summary, "string_prepend" ) @( description, "Create a string variable equal to any text value." ) @( description, "" ) @( description, "Prepend the string variable with another string " ) @( description, "literal." ) @( category, "tutorials" ) @( author, "Ken O. Burtch" ) @( see_also, "http://rosettacode.org/wiki/String_prepend" ); pragma license( unrestricted ); pragma software_model( nonstandard ); pragma restriction( no_external_commands ); procedure string_prepend is world : constant string := "World!"; hello : constant string := "Hello "; s : string; begin -- Using concatenation s := world; s := hello & @; ? s; -- Using strings library s := world; s := strings.insert( @, 1, hello ); ? s; command_line.set_exit_status( 0 ); end string_prepend;</syntaxhighlight> {{out}} <pre> $ spar string_prepend.sp Hello World! Hello World!</pre> =={{header\|Standard ML}}== <syntaxhighlight lang="text"> > val s="any text" ; val s = "any text": string > "prepended " ^ s; val it = "prepended any text": string </syntaxhighlight> =={{header\|Stata}}== <syntaxhighlight lang="stata">sca s="Vita Brevis" sca s="Ars Longa "+s di s Ars Longa Vita Brevis</syntaxhighlight> =={{header\|Swift}}== {{works with\|Swift\|5}} <syntaxhighlight lang="swift">var str = ", World" str = "Hello" + str print(str)</syntaxhighlight> {{out}} <pre> Hello, World! </pre> {{works with\|Swift\|1}} <syntaxhighlight lang="swift">var str = ", World" str = "Hello \(str)" println(str)</syntaxhighlight> {{out}} <pre> Hello, World! </pre> =={{header\|Tcl}}== Concatenation is a fundamental feature of Tcl's basic language syntax. <~~lang~~syntaxhighlight lang="tcl">set s "llo world" set s "he$s" puts $s</~~lang~~syntaxhighlight> {{out}}~~<pre>hello world</pre>~~ <pre>hello world</pre> =={{header\|Ursa}}== <syntaxhighlight lang="ursa">decl string s # set s to "world" set s "world" # prepend "hello " set s (+ "hello " s) # outputs "hello world" out s endl console</syntaxhighlight> =={{header\|VBA}}== <~~lang~~syntaxhighlight VBlang="vb">Function StringPrepend() Dim s As String s = "bar" s = "foo" & s Debug.Print s End Function</~~lang~~syntaxhighlight> =={{header\|VBScript}}== <syntaxhighlight lang="vb">s = "bar" s = "foo" & s WScript.Echo s</syntaxhighlight> {{Out}} <pre>foobar</pre> =={{header\|V (Vlang)}}== <syntaxhighlight lang="v (vlang)">mut s := "world!" s = "Hello, " + s println(s)</syntaxhighlight> {{out}} <pre> Hello, world! </pre> =={{header\|Wart}}== <~~lang~~syntaxhighlight lang="python">s <- "12345678" s <- ("0" + s)</~~lang~~syntaxhighlight> =={{header\|Wren}}== <syntaxhighlight lang="wren">var s = "world!" s = "Hello, " + s System.print(s)</syntaxhighlight> {{out}} <pre> Hello, world! </pre> =={{header\|Xojo}}== <syntaxhighlight lang="vb">Dim s As String = "bar" s = "foo" + s MsgBox(s)</syntaxhighlight> {{Out}} <pre>foobar</pre> =={{header\|XPL0}}== <syntaxhighlight lang="xpl0">include xpllib; char S, T(80); [S:= "world!"; S:= StrCat(StrCopy(T,"Hello, "), S); Text(0, S); ]</syntaxhighlight> {{out}} <pre> Hello, world! </pre> =={{header\|zkl}}== <~~lang~~syntaxhighlight lang="zkl">s:="bar"; s="foo" + s; s.println(); s:=~~Data(0,0,~~"bar"~~).insert~~; s=String(0,"foo",s)~~.text~~; s.println();~~</lang>~~ s:="bar"; s="%s%s".fmt("foo",s); s.println(); // a Data is a byte buffer/editor: s:=Data(Void,"bar").insert(0,"foo").text; s.println();</syntaxhighlight> {{out}} <pre> foobar foobar foobar foobar </pre> ~~{{omit from\|bc\|No string operations in bc}}~~ ~~{{omit from\|dc\|No string operations in dc}}~~