FOR

Runs a block for each of a run of numbers.

Syntax

FOR name = from TO to BEGIN … END
FOR name = from TO to STEP step BEGIN … END

Argument	Meaning
name	The variable that takes each number in turn.
from	The first number: an expression.
to	The last: the loop stops when the next number would go past it.
step	What is added each time round (1 if left out). It can be less than 0, to count down; it can't be 0.

DO may go before BEGIN: FOR I = 1 TO 5 DO BEGIN … END.

Examples

FOR I = 0 TO L STEP 50 BEGIN
    P10 = [I, 0]
    P11 = [I, W]
    LINE P10, P11
END

FOR example

Lines across the box every 50, and as many as fit: change L and there are more, or fewer.

FOR A = 0 TO 330 STEP 30 BEGIN
    P10 = POLAR(P0, A, 100)
    P11 = POLAR(P0, A, 120)
    LINE P10, P11
END

Twelve ticks round P0, as on a clock face.

Notes

from, to and step are worked out once, when the loop starts. The last number is included when the steps land on it (allowing for rounding: FOR I = 0 TO 1 STEP 0.1 runs 11 times).

BREAK leaves the loop; CONTINUE goes on to the next number.

More commands