Editing While loop (section)

===Pascal===
{{Further|Pascal (programming language)}}
Pascal has two forms of the while loop, '''while''' and '''repeat'''. While repeats one statement (unless enclosed in a begin-end block) as long as the condition is true. The repeat statement repetitively executes a block of one or more statements through an '''until''' statement and continues repeating unless the condition is false. The main difference between the two is the while loop may execute zero times if the condition is initially false, the repeat-until loop always executes at least once.

<syntaxhighlight lang="pascal">
program Factorial1;
var
    Fv: integer;

    procedure fact(counter:integer);
    var
        Factorial: integer;

    begin
         Factorial := 1;

         while Counter > 0 do
         begin
             Factorial := Factorial * Counter;
             Counter := Counter - 1
         end;

         WriteLn(Factorial)
     end;

begin
    Write('Enter a number to return its factorial: ');
    readln(fv);
    repeat
         fact(fv);
         Write('Enter another number to return its factorial (or 0 to quit): ');
     until fv=0;
end.
</syntaxhighlight>