method

is_a?

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

is_a?(p1) public

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

Show source

/*
 *  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(obj, c)
    VALUE obj, 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(cl)->m_tbl == RCLASS(c)->m_tbl)
            return Qtrue;
        cl = RCLASS(cl)->super;
    }
    return Qfalse;
}

is_a?

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