具体call、apply的使用方法见本人博客[Call and Apply in JavaScript](http://www.cnblogs.com/zhaoww/p/5247827.html) 4)new绑定 ```javascriptfunctionfoo(a) {this.a= a; }varbar =newfoo(2);console.log( bar.a);// 2``` 使用new调用时,会构造一个对象并将this指向进行绑定。如本例的foo上。 4. 优先级 new绑定>显示绑定>隐式绑定>默认绑定 ------...
functionexecute(){'use strict';functionconcat(str1,str2){// the strict mode is enabled tooconsole.log(this===undefined);// => truereturnstr1+str2;}console.log(this===undefined);// => true// concat() is invoked as a function in strict mode// this in concat() is undefinedconcat('...
[Javascript] this in Function Calls In most cases, the value of a function'sthisargument is determined by how the function is called. This lesson explains whatthisrefers to when we call plain function. Marius points out how functions behave differently in strict and non-strict mode."use stric...
https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Function/call bind Thebind()method creates a new function that, when called, has itsthiskeyword set to the provided value, with a given sequence of arguments preceding any provided when the new function is called....
myNumber = 20; // add 'myNumber' property to global object return a + b; } // sum() is invoked as a function // this in sum() is a global object (window) sum(15, 16); // => 31 window.myNumber; // => 20 当调用 sum(15, 16) 的时候,JavaScript 会自动将 this 指向全局...
[Javascript] this in Function Calls In most cases, the value of a function'sthisargument is determined by how the function is called. This lesson explains whatthisrefers to when we call plain function. Marius points out how functions behave differently in strict and non-strict mode."use ...
function foo() {console.log(this.a);}var obj = {a:2};var bar = function() {foo.call(obj); //this被硬绑定至obj};bar(); //2setTimeout(bar, 100); //2bar.call(window); //2 硬绑定的bar不能再修改它的this •可复用的辅助绑定函数 ...
this in global context this in object construction this in an object method this in a simple function this in an arrow function this in an event listener You may wonder what this is in each context and why there’s a need to change this in the first place. To answer your question, let...
I thought I know the Function definition, execution context and the behavior of this in JavaScript. However, I realized that actually I don't or th...
If you understand the basic rules for converting a sugary function call into a desugaredfunc.call(thisValue, ...args), you should be able to navigate the not so treacherous waters of the JavaScriptthisvalue. PS: I Cheated In several places, I simplified the reality a bit from the exact ...