Chapter 4, Objects
Lets solve the following exercises:
Exercises
- What happens here? What is
thisand what'so?function F() { function C() { return this; } return C(); } var o = new F();Here,
this === windowbecauseC()was called withoutnew.Also
o === windowbecausenew F()returns the object returned byC(), which isthis, andthisiswindow.You can make the call to
C()a constructor call:function F() { function C() { return this; } return new C(); } var o = new F();Here,
thisis the object created by theC()constructor. So iso:> o.constructor.name; "C"It becomes more interesting with ES5's strict mode. In the strict mode, non-constructor invocations result in
thisbeingundefined, not the global object. With"use strict"insideF()orC()constructor's body,thiswould beundefined...
