Loop Statements (for, while, repeat)

For, while, repeat statements

Loop statements are used to repeatedly execute code. You can use for/to statement to iterate from low to high bounds, for/downto to iterate in reverse order, or while or repeat statements to iterate with condition. Examples:

for i := 0 to 10 do

  ShowMessage(i);

for i := 10 downto 0 do

  ShowMessage(i);

i := 1;

while i < 10 do

begin

  ShowMessage(i);

  i := i * 2;

end;

i := 1;

repeat

  ShowMessage(i);

  i := i * 2;
until i >= 10;

Break and Continue

The Break intrinsic function can be used to break loop statement. Continue intrinsic function can be used to go to the next loop iteration. Using Break/Continue outside of the loop will raise run-time error.

i := 1;

while i < 100 do

begin

  if i = 15 then

    Break;

  i := F(i);

end;

for i := 0 to 10 do

begin

  if (i mod 2) <> 0 then

    Continue;

  ShowMessage(i + ' is an even number');

end;

The Break/Continue functions always works with innermost loop:

for i := 0 to 10 do // outer

begin

  if i = 5 then

    Break; // Break outer loop.

  for j := 0 to 10 do // inner

  begin

    if j = 5 then 

      Break; // Break inner loop.

  end;

end;