Method: Object#instance_variable_defined?

Defined in:
object.c

#instance_variable_defined?(symbol) ⇒ Boolean #instance_variable_defined?(string) ⇒ Boolean

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

Overloads:

  • #instance_variable_defined?(symbol) ⇒ Boolean

    Returns:

    • (Boolean)
  • #instance_variable_defined?(string) ⇒ Boolean

    Returns:

    • (Boolean) 


2980
2981
2982
2983
2984
2985
2986
2987
2988
2989
 
# File 'object.c', line 2980

static VALUE
rb_obj_ivar_defined(VALUE obj, VALUE iv)
{
    ID id = id_for_var(obj, iv, instance);

    if (!id) {
        return Qfalse;
    }
    return rb_ivar_defined(obj, id);
}