Method: Range#size

Defined in:
range.c

#size ⇒ Infinity?

Returns the count of elements in self if both begin and end values are numeric; otherwise, returns nil:

(1..4).size      # => 4
(1...4).size     # => 3
(1..).size       # => Infinity
('a'..'z').size  # => nil

If self is not iterable, raises an exception:

(0.5..2.5).size  # TypeError
(..1).size       # TypeError

Related: Range#count.

Returns:

  • (Infinity, nil) 

941
942
943
944
945
946
947
948
949
950
951
952
953
954
955
956
957
958
959
960
 
# File 'range.c', line 941

static VALUE
range_size(VALUE range)
{
    VALUE b = RANGE_BEG(range), e = RANGE_END(range);

    if (RB_INTEGER_TYPE_P(b)) {
        if (rb_obj_is_kind_of(e, rb_cNumeric)) {
            return ruby_num_interval_step_size(b, e, INT2FIX(1), EXCL(range));
        }
        if (NIL_P(e)) {
            return DBL2NUM(HUGE_VAL);
        }
    }

    if (!discrete_object_p(b)) {
        CANT_ITERATE_FROM(b);
    }

    return Qnil;
}