Substring/Top and tail

Substring/Top and tail
You are encouraged to solve this task according to the task description, using any language you may know.

The task is to demonstrate how to remove the first and last characters from a string. The solution should demonstrate how to obtain the following results:

• String with first character removed
• String with last character removed
• String with both the first and last characters removed

ALGOL 68

Translation of: AWK

Works with: ALGOL 68 version Revision 1 - no extensions to language used.

Works with: ALGOL 68G version Any - tested with release 1.18.0-9h.tiny.

<lang algol68>#!/usr/local/bin/a68g --script #

STRING str="upraisers"; printf(($gl$,

 str,                      # remove no characters #
 str[LWB str+1:         ], # remove the first character #
 str[         :UPB str-1], # remove the last character #
 str[LWB str+1:UPB str-1], # remove both the first and last character #
 str[LWB str+2:         ], # remove the first 2 characters #
 str[         :UPB str-2], # remove the last 2 characters #
 str[LWB str+1:UPB str-2], # remove 1 before and 2 after #
 str[LWB str+2:UPB str-1], # remove 2 before and one after #
 str[LWB str+2:UPB str-2]  # remove both the first and last 2 characters #

))</lang> Output:

upraisers
praisers
upraiser
praiser
raisers
upraise
praise
raiser
raise

AWK

<lang awk>BEGIN {

 mystring="knights"
 print substr(mystring,2)                       # remove the first letter
 print substr(mystring,1,length(mystring)-1)    # remove the last character
 print substr(mystring,2,length(mystring)-2)    # remove both the first and last character

}</lang>

Icon and Unicon

The task is accomplished by sub-stringing. <lang Icon>procedure main() write(s := "knight"," --> ", s[2:0]) # drop 1st char write(s := "sock"," --> ", s[1:-1]) # drop last write(s := "brooms"," --> ", s[2:-1]) # drop both end</lang>

It could also be accomplished (less clearly) by assigning into the string as below. Very awkward for both front and back. <lang Icon>write(s := "knight"," --> ", s[1] := "", s) # drop 1st char</lang>

J

The monadic primitives }. (Behead) and }: (Curtail) are useful for this task.

Example use:
<lang j> }. 'knight' NB. drop first item night

  }: 'socks'       NB. drop last item

sock

  }: }. 'brooms'   NB. drop first and last items

room</lang>

JavaScript

<lang javascript>alert("knight".slice(1)); // strip first character alert("socks".slice(0, -1)); // strip last character alert("brooms".slice(1, -1)); // strip both first and last characters</lang>

Lua

<lang lua>print (string.sub("knights",2)) -- remove the first character print (string.sub("knights",1,-2)) -- remove the last character print (string.sub("knights",2,-2)) -- remove the first and last characters</lang>

PARI/GP

<lang parigp>df(s)=concat(vecextract(Vec(s),1<<#s-2)); dl(s)=concat(vecextract(Vec(s),1<<(#s-1)-1)); db(s)=concat(vecextract(Vec(s),1<<(#s-1)-2));</lang>

Perl

<lang perl>print substr("knight",1), "\n"; # strip first character print substr("socks", 0, -1), "\n"; # strip last character print substr("brooms", 1, -1), "\n"; # strip both first and last characters</lang>

In perl, we can also remove the last character from a string variable with the chop function:

<lang perl>$string = 'ouch'; $bits = chop($string); # The last letter is returned by the chop function print $bits; # h print $string; # ouc # See we really did chop the last letter off</lang>

PHP

<lang php><?php echo substr("knight", 1), "\n"; // strip first character echo substr("socks", 0, -1), "\n"; // strip last character echo substr("brooms", 1, -1), "\n"; // strip both first and last characters ?></lang>

PicoLisp

<lang PicoLisp>: (pack (cdr (chop "knight"))) # Remove first character -> "night"

(pack (head -1 (chop "socks"))) # Remove last character

-> "sock"

(pack (cddr (rot (chop "brooms")))) # Remove first and last characters

-> "room"</lang>

Prolog

Works with SWI-Prolog.

<lang Prolog>remove_first_last_chars :- L = "Rosetta", L = [_|L1], remove_last(L, L2), remove_last(L1, L3), writef('Original string  : %s\n', [L]), writef('Without first char  : %s\n', [L1]), writef('Without last char  : %s\n', [L2]), writef('Without first/last chars : %s\n', [L3]).

remove_last(L, LR) :- reverse(L, [_ | L1]), reverse(L1, LR).</lang> Output :

 ?- remove_first_last_chars.
Original string          : Rosetta
Without first char       : osetta
Without last char        : Rosett
Without first/last chars : osett
true.

PureBasic

<lang PureBasic>If OpenConsole()

 PrintN(Right("knight", Len("knight") - 1))  ;strip the first letter
 PrintN(Left("socks", Len("socks")- 1))      ;strip the last letter
 PrintN(Mid("brooms", 2, Len("brooms") - 2)) ;strip both the first and last letter
 
 Print(#CRLF$ + #CRLF$ + "Press ENTER to exit"): Input()
 CloseConsole()

EndIf</lang> Sample output:

night
sock
room

Python

<lang python>print "knight"[1:] # strip first character print "socks"[:-1] # strip last character print "brooms"[1:-1] # strip both first and last characters</lang>

Ruby

<lang ruby>puts "knight"[1..-1] # strip first character puts "socks"[0..-2] # strip last character puts "socks".chop # alternate way to strip last character puts "brooms"[1..-2] # strip both first and last characters</lang>

Tcl

<lang tcl>puts [string range "knight" 1 end]; # strip first character puts [string range "write" 0 end-1]; # strip last character puts [string range "brooms" 1 end-1]; # strip both first and last characters</lang>

ZX Spectrum Basic

<lang zxbasic>10 PRINT FN f$("knight"): REM strip the first letter 20 PRINT FN l$("socks"): REM strip the last letter 30 PRINT FN b$("brooms"): REM strip both the first and last letter 100 STOP

9000 DEF FN f$(a$)=a$(2 TO LEN(a$)) 9010 DEF FN l$(a$)=a$(1 TO LEN(a$)-(1 AND (LEN(a$)>=1))) 9020 DEF FN b$(a$)=FN l$(FN f$(a$)) </lang>