method

count

v1_8_7_72 - Show latest stable - 0 notes - Class: Array

count(...) public

Returns the number of elements. If an argument is given, counts the number of elements which equals to obj. 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

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/*
 *  call-seq:
 *     array.count      -> int
 *     array.count(obj) -> int
 *     array.count { |item| block }  -> int
 *  
 *  Returns the number of elements.  If an argument is given, counts
 *  the number of elements which equals to <i>obj</i>.  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
rb_ary_count(argc, argv, ary)
    int argc;
    VALUE *argv;
    VALUE ary;
{
    long n = 0;

    if (argc == 0) {
        VALUE *p, *pend;

        if (!rb_block_given_p())
            return LONG2NUM(RARRAY_LEN(ary));

        for (p = RARRAY_PTR(ary), pend = p + RARRAY_LEN(ary); p < pend; p++) {
            if (RTEST(rb_yield(*p))) n++;
        }
    }
    else {
        VALUE obj, *p, *pend;

        rb_scan_args(argc, argv, "1", &obj);
        if (rb_block_given_p()) {
            rb_warn("given block not used");
        }
        for (p = RARRAY_PTR(ary), pend = p + RARRAY_LEN(ary); p < pend; p++) {
            if (rb_equal(*p, obj)) n++;
        }
    }

    return LONG2NUM(n);
}

count

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