nitems

/*
 *  call-seq:
 *     array.nitems -> int
 *  
 *  Returns the number of non-<code>nil</code> elements in _self_.
 *
 *  May be zero.
 *     
 *     [ 1, nil, 3, nil, 5 ].nitems   #=> 3
 */

static VALUE
rb_ary_nitems(ary)
    VALUE ary;
{
    long n = 0;
    VALUE *p, *pend;

    for (p = RARRAY(ary)->ptr, pend = p + RARRAY(ary)->len; p < pend; p++) {
        if (!NIL_P(*p)) n++;
    }
    return LONG2NUM(n);
}