Up: The for Statement [Contents][Index]
A special form of the for
statement allows you to loop over all
the elements of a structure:
for [ val, key ] = expression body endfor
In this form of the for
statement, the value of expression
must be a structure. If it is, key and val are set to the
name of the element and the corresponding value in turn, until there are
no more elements. For example:
x.a = 1 x.b = [1, 2; 3, 4] x.c = "string" for [val, key] = x key val endfor -| key = a -| val = 1 -| key = b -| val = -| -| 1 2 -| 3 4 -| -| key = c -| val = string
The elements are not accessed in any particular order. If you need to
cycle through the list in a particular way, you will have to use the
function fieldnames
and sort the list yourself.