You are viewing the version of this documentation from Perl 5.6.1. View the latest version
splice ARRAY,OFFSET,LENGTH,LIST
splice ARRAY,OFFSET,LENGTH
splice ARRAY,OFFSET
splice ARRAY

Removes the elements designated by OFFSET and LENGTH from an array, and replaces them with the elements of LIST, if any. In list context, returns the elements removed from the array. In scalar context, returns the last element removed, or undef if no elements are removed. The array grows or shrinks as necessary. If OFFSET is negative then it starts that far from the end of the array. If LENGTH is omitted, removes everything from OFFSET onward. If LENGTH is negative, leaves that many elements off the end of the array. If both OFFSET and LENGTH are omitted, removes everything.

The following equivalences hold (assuming $[ == 0):

push(@a,$x,$y)      splice(@a,@a,0,$x,$y)
pop(@a)             splice(@a,-1)
shift(@a)           splice(@a,0,1)
unshift(@a,$x,$y)   splice(@a,0,0,$x,$y)
$a[$x] = $y         splice(@a,$x,1,$y)

Example, assuming array lengths are passed before arrays:

sub aeq {   # compare two list values
    my(@a) = splice(@_,0,shift);
    my(@b) = splice(@_,0,shift);
    return 0 unless @a == @b;       # same len?
    while (@a) {
        return 0 if pop(@a) ne pop(@b);
    }
    return 1;
}
if (&aeq($len,@foo[1..$len],0+@bar,@bar)) { ... }