Javascript绑定对象文字方法不起作用

Question

The bind method does not transfer the 't' variable as the new 'this' keyword to the "ob.bind_part()' object literal function?

 var ob = { "first": function() { console.log("first function"); var t = "new bind"; ob.bind_part.bind(t); }, "bind_part": function() { console.log(this.toString()); } }; (function() { ob.first(); ob.bind_part(); // returns the 'ob' object instead of the bind })(); 

However, instead of bind if 'call' is used

 ob.bind_part.call(t); //THIS WORKS

it works?

any idea why bind does not work?

thanks

Answer 1

Function.bind returns a new function, you have to assign it to obj.bind_part

 var ob = { "first": function() { console.log("first function"); var t = "new bind"; ob.bind_part = ob.bind_part.bind(t); }, "bind_part": function() { console.log(this.toString()); } }; (function() { ob.first(); ob.bind_part(); // returns "new bind" })(); 

Answer 2

The .bind() method does not mutate a function, instead it returns a new one. You're not doing anything with the return value. The following would work:

ob.bind_part = ob.bind_part.bind(t);

Answer 3

.bind()返回一个新函数，您需要将其分配回调用对象。

ob.bind_part = ob.bind_part.bind(t);