x undefined? true
TypeError: Cannot read property "foo" from undefined
TypeError: Cannot set property "bar" of undefined
TypeError: Cannot read property "1" from undefined
TypeError: Cannot set property "0" of undefined
TypeError: Cannot read property "func" from undefined
TypeError: Cannot delete property "0" of undefined
TypeError: Cannot delete property "foo" of undefined
TypeError: undefined is not an Object
TypeError: Cannot apply "with" to undefined