Loops/Increment loop index within loop body: Difference between revisions

[ f.incr replace ] is incr ( n --> )

[ f.end replace ] is end ( b --> )

The default increment is <code>1</code>, but this can be overridden for a single iteration by the word <code>incr</code> within the nest being performed by <code>from</code>. <code>incr</code> takes a number from the stack, and sets the increment to that number for the current iteration. If <code>incr</code> is performed within some iterations but not all, the increment will be <code>1</code> for those iterations where it is not performed.

The task states "''in addition to the normal incrementation''" but this is counter-intuitive. To make the loop task compliant you will need to precede <code>f.incr</code> with <code>1+</code> in <code>incr</code>. You will also need to delete the <code>1+</code> before <code>incr</code> in the task code below.

The word <code>end</code> sets the ending condition to the boolean it takes from the stack, so the loop will end at the end of the current iteration if the boolean is <code>true</code>.

index 1+ incr ]

dup 42 = end ]