Method: Array#insert

Defined in:
array.c

#insert(index, obj...) ⇒ Array

Inserts the given values before the element with the given index.

Negative indices count backwards from the end of the array, where -1 is the last element. If a negative index is used, the given values will be inserted after that element, so using an index of -1 will insert the values at the end of the array.

a = %w{ a b c d }
a.insert(2, 99)         #=> ["a", "b", 99, "c", "d"]
a.insert(-2, 1, 2, 3)   #=> ["a", "b", 99, "c", 1, 2, 3, "d"]

Returns:



1749
1750
1751
1752
1753
1754
1755
1756
1757
1758
1759
1760
1761
1762
1763
1764
1765
1766
 
# File 'array.c', line 1749

static VALUE
rb_ary_insert(int argc, VALUE *argv, VALUE ary)
{
    long pos;

    rb_check_arity(argc, 1, UNLIMITED_ARGUMENTS);
    rb_ary_modify_check(ary);
    if (argc == 1) return ary;
    pos = NUM2LONG(argv[0]);
    if (pos == -1) {
	pos = RARRAY_LEN(ary);
    }
    if (pos < 0) {
	pos++;
    }
    rb_ary_splice(ary, pos, 0, rb_ary_new4(argc - 1, argv + 1));
    return ary;
}