Loops/Infinite: Difference between revisions
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print "SPAM"</lang> |
print "SPAM"</lang> |
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Note: one can also use: "True" or any other non-false value. In Python the following values are false: 0, "" (empty string), (,) and {} and [] (empty tuples, dictionaries or lists), ''None'' (the special object), and the ''False'' object. Any non-empty collection or string or non-zero numeric value is considered "True" |
Note: one can also use: "True" or any other non-false value. In Python the following values are false: 0, "" (empty string), (,) and {} and [] (empty tuples, dictionaries or lists), ''None'' (the special object), and the ''False'' object. Any non-empty collection or string or non-zero numeric value is considered "True". However, according to [http://wiki.python.org/moin/PythonSpeed#Takeadvantageofinterpreteroptimizations Python Wiki], for Python versions 2.3+ this variant is optimized by the interpreter and thus is the fastest. |
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=={{header|R}}== |
=={{header|R}}== |
Revision as of 20:32, 28 March 2010
You are encouraged to solve this task according to the task description, using any language you may know.
Specifically print out "SPAM" followed by a newline in an infinite loop.
ActionScript
<lang actionscript>while (true) {
trace("SPAM");
}</lang>
Ada
<lang ada>loop
Put_Line("SPAM");
end loop;</lang>
ALGOL 68
<lang algol68>DO
printf($"SPAM"l$)
OD</lang> Or the classic "dynamic halt": <lang algol68>loop x:
printf($"SPAM"l$);
loop x</lang>
AmigaE
<lang amigae>PROC main()
LOOP WriteF('SPAM') ENDLOOP
ENDPROC</lang>
AutoHotkey
<lang autohotkey>Loop
MsgBox SPAM `n</lang>
AWK
<lang awk>BEGIN {
while(1) { print "SPAM" }
}</lang>
BASIC
Old-fashioned syntax: <lang qbasic>while 1
print "SPAM"
wend</lang>
Standard BASIC: <lang qbasic>do
print "SPAM"
loop</lang>
Also <lang qbasic>for i = 1 to 10 step 0
print "SPAM"
next i</lang>
With classic (minimal) BASIC, the standard way to make an infinite loop would be:
10 PRINT "SPAM" 20 GOTO 10
Befunge
Because the 2-D code space is toroidal, all loops are infinite unless explicitly stopped with @. <lang befunge>55+"MAPS",,,,,</lang>
Brainf***
<lang bf>++++++++++[->++++++>++++++++>+<<<]>+++++> [+++.---.<.>---.+++>.<]</lang>
C
<lang c>while(1) puts("SPAM\n");</lang> or <lang c> for(;;) puts("SPAM\n");</lang> or <lang c>do { puts("SPAM\n"); } while(1);</lang>
C++
<lang cpp>while (true)
std::cout << "SPAM\n";</lang>
or <lang cpp>for (;;)
std::cout << "SPAM\n";</lang>
or <lang cpp>do
std::cout << "SPAM\n";
while (true);</lang>
C#
<lang csharp>while (true) {
Console.WriteLine("SPAM");
}</lang>
ColdFusion
This will result in a JRun Servlet Error and heap dump.
With tags: <lang cfm><cfloop condition = "true NEQ false">
SPAM
</cfloop></lang> With script: <lang cfm><cfscript>
while( true != false ) { writeOutput( "SPAM" ); }
</cfscript></lang>
Clojure
<lang lisp>(loop [] (println "SPAM") (recur))</lang>
Common Lisp
<lang lisp>(loop (write-line "SPAM"))</lang>
D
<lang d>while(true) writefln("SPAM") ;</lang> <lang d>for(;;) writefln("SPAM") ;</lang> <lang d>l: writefln("SPAM"); goto l;</lang>
E
<lang e>while (true) {
println("SPAM")
}</lang>
<lang e>def f() {
println("SPAM") f <- ()
} f <- ()</lang>
The difference between these is that in the second, other activities can be interleaved with the loop; in the first, no other processing will occur in this vat.
Erlang
<lang erlang>-module (main). -export ([main/1]).
main(Any) ->
io:fwrite("SPAM~n",[]), main(Any)</lang>
Factor
<lang factor>: spam ( -- ) "SPAM" print spam ;</lang> <lang factor>: spam ( -- ) [ "SPAM" print t ] loop ;</lang>
FALSE
<lang false>[1]["SPAM "]#</lang>
Forth
<lang forth>: email begin ." SPAM" cr again ;</lang>
Fortran
<lang fortran>DO
WRITE(*,*) "SPAM"
END DO</lang> Although deprecated GOTO is still available <lang fortran>10 WRITE(*,*) "SPAM"
GOTO 10</lang>
Go
<lang go>package main import "fmt" func main() { for { fmt.Printf("SPAM\n") } }</lang>
Groovy
<lang groovy>while (true) {
println 'SPAM'
}</lang>
Haskell
<lang haskell>forever (putStrLn "SPAM")</lang>
HicEst
<lang hicest>DO i = 1, 1E20 ! for i with 16 or more digits: i == i + 1 == loop infinite
WRITE() "SPAM"
ENDDO</lang>
Icon
<lang icon>procedure main()
every write(|"SPAM")
end</lang>
IDL
<lang IDL>while 1 do print,'SPAM'</lang>
Io
<lang io>loop("SPAM" println)</lang>
J
<lang j>-@:(][ 1!:2&2@('SPAM'"_)) (^:_) 1</lang>
Alternatively,
<lang j>smoutput bind 'SPAM'^:1e99 </lang>
This implementation relies on numeric inaccuracies in IEEE floating point notation. For example, 1+1e98 is exactly equal to 1e98. That said, 1e99 iterations would still be significantly longer than the practical life of any machine anyone would care to dedicate to this task.
Java
<lang java>while(true){
System.out.println("SPAM");
}</lang>
<lang java>for(;;){
System.out.println("SPAM");
}</lang>
JavaScript
<lang javascript>for (;;) print("SPAM"); while (true) print("SPAM");</lang>
Joy
<lang joy>DEFINE loop == [1] swap while.
["SPAM\n" putchars] loop.</lang>
Lisaac
The "lisaac" compiler apparently doesn't like infinite loops. Using a static slot (variable) seems to be the only way to get away with "Recursivity without end (call_slot)." error. <lang Lisaac>- i : INTEGER; i := 1; { i = 1 }.while_do {
"SPAM\n".print;
};</lang>
Logo
<lang logo>forever [print "SPAM]</lang>
Lua
<lang lua> while 1 do
print("SPAM")
end </lang>
M4
<lang M4>define(`spam',`SPAM spam') spam</lang>
Make
<lang make>spam:
@echo SPAM $(MAKE)</lang>
MAXScript
<lang maxscript>while true do print "SPAM\n"</lang>
Metafont
<lang metafont>forever: message "SPAM"; endfor end</lang>
Modula-3
<lang modula3>LOOP
IO.Put("SPAM\n");
END;</lang>
MOO
<lang moo>while (1)
player:tell("SPAM");
endwhile</lang>
OCaml
<lang ocaml>while true do
print_endline "SPAM"
done</lang>
or
<lang ocaml>let rec inf_loop() =
print_endline "SPAM"; inf_loop()
in inf_loop()</lang>
Seen like this it looks like the "too much functional" danger when a "while" loop looks far simpler, but the functional loop may be useful to provide data to the next loop without using mutable variable.
Octave
<lang octave>while(1)
disp("SPAM")
endwhile</lang>
Oz
<lang oz>for do
{Show 'SPAM'}
end</lang>
Pascal
<lang pascal>while true do
writeln('SPAM');</lang>
Alternatively: <lang pascal>repeat
writeln('SPAM')
until false;</lang>
Perl
<lang perl>print "SPAM\n" while 1;</lang>
Perl 6
<lang perl6>loop {
say 'SPAM';
}</lang>
PHP
<lang php>while(1)
echo "SPAM\n";</lang>
PicoLisp
<lang PicoLisp>(loop (prinl "SPAM"))</lang>
Pike
<lang pike>int main(){
while(1) write("SPAM\n");
}</lang>
PL/I
<lang PL/I> do forever;
put list ('SPAM'); put skip;
end; </lang>
Pop11
<lang pop11>while true do
printf('SPAM', '%p\n');
endwhile;</lang>
PowerShell
<lang powershell>for () {
"SPAM"
}</lang>
Prolog
<lang prolog>repeat, write('SPAM'), nl, fail.</lang>
PureBasic
<lang PureBasic>Repeat
PrintN("SPAM")
ForEver</lang>
Python
<lang python>while 1:
print "SPAM"</lang>
Note: one can also use: "True" or any other non-false value. In Python the following values are false: 0, "" (empty string), (,) and {} and [] (empty tuples, dictionaries or lists), None (the special object), and the False object. Any non-empty collection or string or non-zero numeric value is considered "True". However, according to Python Wiki, for Python versions 2.3+ this variant is optimized by the interpreter and thus is the fastest.
R
Note that the default R Gui buffers outputs before pushing them to the screen. To see this run either run in terminal mode, right click on the GUI window and deselect "Buffered Output" prior to execution, or add a call to flush.console() in the loop.
<lang R>repeat print("SPAM")</lang>
REBOL
<lang REBOL>forever [print "SPAM"]</lang>
REXX
<lang rexx>do forever
say "SPAM"
end</lang>
Ruby
<lang ruby>loop do
puts "SPAM"
end</lang>
Scheme
<lang scheme>(do ()
(#f) (display "SPAM") (newline))</lang>
Slate
<lang slate>[inform: 'SPAM'] loop</lang>
Smalltalk
<lang smalltalk>[ true ] whileTrue: [ 'SPAM' displayNl ]</lang>
SNUSP
<lang snusp>@\>@\>@\>@\>++++++++++===!/ < < < < \
| | | \M=@@@@+@+++++# \.>.>.>.>./ | | \A=@@+@@@@+++# | \P=@@+@@+@@+++# \S=@@+@+@@@+++#</lang>
Standard ML
<lang sml>while true do
print "SPAM\n";</lang>
or
<lang sml>let
fun inf_loop () = ( print "SPAM\n"; inf_loop () )
in
inf_loop ()
end</lang>
Seen like this it looks like the "too much functional" danger when a "while" loop looks far simpler, but the functional loop may be useful to provide data to the next loop without using mutable variable.
Transact-SQL
<lang sql>WHILE 1=1 BEGIN
PRINT "SPAM"
END</lang>
Tcl
<lang tcl>while true {
puts SPAM
}
- or
for {} 1 {} {
puts SPAM
}</lang>
TI-89 BASIC
<lang ti89b>Loop
Disp "SPAM"
EndLoop</lang>
UNIX Shell
<lang bash>while :; do echo SPAM; done</lang>
UnixPipes
<lang bash> yes SPAM</lang>
Unlambda
<lang unlambda> ``ci``s``s`kr``s``s``s``s`k.S`k.P`k.A`k.Mii</lang>
V
<lang v>true [
'SPAM' puts
] while</lang>
Vedit macro language
<lang vedit>while (1) {
Message("Spam\n")
}</lang> or: <lang vedit>do {
Message("Spam\n")
} while (1)</lang> or: <lang vedit>for (;1;) {
Message("Spam\n")
}</lang> "Nearly infinite" loop can be done by using constant ALL (=1073741824) as repeat count: <lang vedit>Repeat (ALL) {
Message("Spam\n")
}</lang>
Visual Basic
<lang vb>Do
Debug.Print("SPAM")
Loop</lang>
Visual Basic .NET
Platform: .NET
<lang vbnet>Do
Console.WriteLine("SPAM")
Loop</lang>
- Programming Tasks
- Iteration
- ActionScript
- Ada
- ALGOL 68
- AmigaE
- AutoHotkey
- AWK
- BASIC
- Befunge
- Brainf***
- C
- C++
- C sharp
- ColdFusion
- Clojure
- Common Lisp
- D
- E
- Erlang
- Factor
- FALSE
- Forth
- Fortran
- Go
- Groovy
- Haskell
- HicEst
- Icon
- IDL
- Io
- J
- Java
- JavaScript
- Joy
- Lisaac
- Logo
- Lua
- M4
- Make
- MAXScript
- Metafont
- Modula-3
- MOO
- OCaml
- Octave
- Oz
- Pascal
- Perl
- Perl 6
- PHP
- PicoLisp
- Pike
- PL/I
- Pop11
- PowerShell
- Prolog
- PureBasic
- Python
- R
- REBOL
- REXX
- Ruby
- Scheme
- Slate
- Smalltalk
- SNUSP
- Standard ML
- Transact-SQL
- Tcl
- TI-89 BASIC
- UNIX Shell
- UnixPipes
- Unlambda
- V
- Vedit macro language
- Visual Basic
- Visual Basic .NET