This is detailed in JavaScript

Objective

This

This is detailed in JavaScript

This detailed

　　

How many cases does this point to? How is human control?

"Who calls This,this point to who!!" 】

"This point, do not care where this is written!! Only care about the function that contains this, who calls!! 】

① through () direct call, this point to Window func ();

The ② object. The function call, this points to the current object. Obj.func () Div.onclick = function () {}

③ array subscript called, this points to the current array [func,1,2,3]---àarr[0] ();

④ the callback function for all built-in functions, this points to window SetTimeOut (function () {},1000);

Human control:

The ⑤ is called by the New keyword, which points to the empty object that is newly created. Var obj = new func () {} this-obj

⑥ is called by call, apply, bind and this points to the object we specify.

Func.call (obj, parameter one, parameter 2, Parameter 3 ....) )

Func.allply (obj,[parameter one, parameter 2, Parameter 3 ....) ])

Func.bind (obj) (parameter I, parameter 2, parameter 3) var f = func.bind (obj). f (...);

This is detailed in JavaScript