splice - add or remove elements anywhere in an array

NAME

splice - add or remove elements anywhere in an array

SYNOPSIS

splice ARRAY,OFFSET,LENGTH,LIST

splice ARRAY,OFFSET,LENGTH

splice ARRAY,OFFSET

DESCRIPTION

Removes the elements designated by OFFSET and LENGTH from an array, and replaces them with the elements of LIST, if any. Returns the elements removed from the array. The array grows or shrinks as necessary. If LENGTH is omitted, removes everything from OFFSET onward. The following equivalences hold (assuming $[ == 0):

    push(@a,$x,$y)	splice(@a,$#a+1,0,$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
	local(@a) = splice(@_,0,shift);
	local(@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)) { ... }