Method: Object#kind_of?

Defined in:
object.c

#is_a?Boolean #kind_of?Boolean

Returns true if class is the class of obj, or if class is one of the superclasses of obj or modules included in obj.

module M;    end
class A
  include M
end
class B < A; end
class C < B; end
b = B.new
b.instance_of? A   #=> false
b.instance_of? B   #=> true
b.instance_of? C   #=> false
b.instance_of? M   #=> false
b.kind_of? A       #=> true
b.kind_of? B       #=> true
b.kind_of? C       #=> false
b.kind_of? M       #=> true

Overloads:

  • #is_a?Boolean

    Returns:

    • (Boolean)
  • #kind_of?Boolean

    Returns:

    • (Boolean)

# File 'object.c'

/*
 *  call-seq:
 *     obj.is_a?(class)       -> true or false
 *     obj.kind_of?(class)    -> true or false
 *
 *  Returns <code>true</code> if <i>class</i> is the class of
 *  <i>obj</i>, or if <i>class</i> is one of the superclasses of
 *  <i>obj</i> or modules included in <i>obj</i>.
 *
 *     module M;    end
 *     class A
 *       include M
 *     end
 *     class B < A; end
 *     class C < B; end
 *     b = B.new
 *     b.instance_of? A   #=> false
 *     b.instance_of? B   #=> true
 *     b.instance_of? C   #=> false
 *     b.instance_of? M   #=> false
 *     b.kind_of? A       #=> true
 *     b.kind_of? B       #=> true
 *     b.kind_of? C       #=> false
 *     b.kind_of? M       #=> true
 */

VALUE
rb_obj_is_kind_of(VALUE obj, VALUE c)
{
    VALUE cl = CLASS_OF(obj);

    switch (TYPE(c)) {
      case T_MODULE:
      case T_CLASS:
      case T_ICLASS:
    break;

      default:
    rb_raise(rb_eTypeError, "class or module required");
    }

    while (cl) {
    if (cl == c || RCLASS_M_TBL(cl) == RCLASS_M_TBL(c))
        return Qtrue;
    cl = RCLASS_SUPER(cl);
    }
    return Qfalse;
}