method

instance_variable_defined?

v2_2_9 - Show latest stable - 0 notes - Class: Object

instance_variable_defined?(p1) public

Returns true if the given instance variable is defined in obj. String arguments are converted to symbols.

class Fred
  def initialize(p1, p2)
    @a, @b = p1, p2
  end
end
fred = Fred.new('cat', 99)
fred.instance_variable_defined?(:@a)    #=> true
fred.instance_variable_defined?("@b")   #=> true
fred.instance_variable_defined?("@c")   #=> false

Show source

static VALUE
rb_obj_ivar_defined(VALUE obj, VALUE iv)
{
    ID id = rb_check_id(&iv);

    if (!id) {
        if (rb_is_instance_name(iv)) {
            return Qfalse;
        }
        else {
            rb_name_error_str(iv, "`%"PRIsVALUE"' is not allowed as an instance variable name",
                              QUOTE(iv));
        }
    }
    if (!rb_is_instance_id(id)) {
        rb_name_error(id, "`%"PRIsVALUE"' is not allowed as an instance variable name",
                      QUOTE_ID(id));
    }
    return rb_ivar_defined(obj, id);
}

instance_variable_defined?

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