Evaluate a group of commands for each value in a list.

foreach(<loop_var> <items>)

where <items> is a list of items that are separated by semicolon or whitespace. All commands between foreach and the matching endforeach are recorded without being invoked. Once the endforeach is evaluated, the recorded list of commands is invoked once for each item in <items>. At the beginning of each iteration the variable loop_var will be set to the value of the current item.

The commands break() and continue() provide means to escape from the normal control flow.

Per legacy, the endforeach() command admits an optional <loop_var> argument. If used, it must be a verbatim repeat of the argument of the opening foreach command.

foreach(<loop_var> RANGE <stop>)

In this variant, foreach iterates over the numbers 0, 1, … up to (and including) the nonnegative integer <stop>.

foreach(<loop_var> RANGE <start> <stop> [<step>])

In this variant, foreach iterates over the numbers from <start> up to at most <stop> in steps of <step>. If <step> is not specified, then the step size is 1. The three arguments <start> <stop> <step> must all be nonnegative integers, and <stop> must not be smaller than <start>; otherwise you enter the danger zone of undocumented behavior that may change in future releases.

foreach(loop_var IN [LISTS [<lists>]] [ITEMS [<items>]])

In this variant, <lists> is a whitespace or semicolon separated list of list-valued variables. The foreach command iterates over each item in each given list. The <items> following the ITEMS keyword are processed as in the first variant of the foreach command. The forms LISTS A and ITEMS ${A} are equivalent.

The following example shows how the LISTS option is processed:

set(A 0;1)
set(B 2 3)
set(C "4 5")
set(D 6;7 8)
set(E "")
foreach(X IN LISTS A B C D E)
    message(STATUS "X=${X}")


-- X=0
-- X=1
-- X=2
-- X=3
-- X=4 5
-- X=6
-- X=7
-- X=8