=over =item push ARRAY,LIST X X =item push EXPR,LIST Treats ARRAY as a stack by appending the values of LIST to the end of ARRAY. The length of ARRAY increases by the length of LIST. Has the same effect as for $value (LIST) { $ARRAY[++$#ARRAY] = $value; } but is more efficient. Returns the number of elements in the array following the completed C. Starting with Perl 5.14, C can take a scalar EXPR, which must hold a reference to an unblessed array. The argument will be dereferenced automatically. This aspect of C is considered highly experimental. The exact behaviour may change in a future version of Perl. =back