method

count

v1_9_1_378 - Show latest stable - Class: Enumerable

count(p1)

public

Returns the number of items in enum, where #size is called if it responds to it, otherwise the items are counted through enumeration. If an argument is given, counts the number of items in enum, for which equals to item. If a block is given, counts the number of elements yielding a true value.

ary = [1, 2, 4, 2]
ary.count             # => 4
ary.count(2)          # => 2
ary.count{|x|x%2==0}  # => 3

static VALUE
enum_count(int argc, VALUE *argv, VALUE obj)
{
    VALUE memo[2];      /* [count, condition value] */
    rb_block_call_func *func;

    if (argc == 0) {
        if (rb_block_given_p()) {
            func = count_iter_i;
        }
        else {
            if (rb_respond_to(obj, id_size)) {
                return rb_funcall(obj, id_size, 0, 0);
            }
            func = count_all_i;
        }
    }
    else {
        rb_scan_args(argc, argv, "1", &memo[1]);
        if (rb_block_given_p()) {
            rb_warn("given block not used");
        }
        func = count_i;
    }

    memo[0] = 0;
    rb_block_call(obj, id_each, 0, 0, func, (VALUE)&memo);
    return INT2NUM(memo[0]);
}

count

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