Programming Perl, 4th Edition

pop

pop ARRAY
pop

This function treats an array like a stack—it pops (removes) and returns the last value of the array, shortening the array by one element. If ARRAY is omitted, the function pops @_ within the lexical scope of subroutines and formats; it pops @ARGV at file scopes (typically the main program) or within the lexical scopes established by the eval STRING, BEGIN {}, CHECK {}, UNITCHECKINIT {}, and END {} constructs. It has the same effect as:

$tmp = $ARRAY[$#ARRAY––];

or:

$tmp = splice @ARRAY, –1;

If there are no elements in the array, pop returns undef. (But don’t depend on that to tell you when the array is empty if your array contains undef values!) See also push and shift. If you want to pop more than one element, use splice.

The pop requires its first argument to be an array, not a list. If you just want the last element of a list, use this:

( LIST )[–1]

Starting with v5.14, pop can take a reference to an unblessed array, which will be dereferenced automatically. This aspect of pop is considered experimental. The exact behavior may change in a future version of Perl.