This and the name attribute of the window object and the window object in javaScript

Once the page is opened, it is the first run, and the run results are as follows:

For the second run, the results are as follows:

<!DOCTYPE html>
<html>
<head>
<meta charset="UTF-8">
<title>javaScript中this以及window对象和window对象的name属性</title>
<script type="text/javascript">
//打开浏览器，执行本页面所有的代码，第一次执行和第二次执行，运行结果会不同，大家可以试一下

//全局变量(全局变量是属于window对象的属性)
var hometown = "江西省赣州市于都县渡江大道666666号";
console.log(window.hometown, hometown);//window可以省略不写

var salary = 19800.56;
//19800.56 19800.56 19800.56
console.log(salary, window['salary'], window.salary);
//window['salary']这样写才对，如下这种写法不可以
console.log(window[salary]);//undefined

console.log(window, this);
console.log(window == this, window === this); //true true

function Dog(str) {
	this.name = str;
}

var dog1 = new Dog('旺财');
console.log(dog1.name); //结果  
console.log(name); //结果

//在js中window对象有name属性，name属性的值默认是""空字符
console.log(window.name);
console.log(name); //window可以省略不写

function fn(str) {
	console.log("hello" + str, this);
	this.name = str;
	this.age = 26;
}
//如果把下面这2行代码注释掉，运行效果会大不相同，大家可以试一试，会学习到一些意想不到的知识
window.fn("令狐冲");
fn("韦小宝");

var f = new fn("张无忌");

console.log(f.name, f.age);
console.log(name);
console.log(name, age);
console.log(window.name, window.age);

function Person(str) {
	this.userName = str;
	this.userAge = 12;
}

var p1 = new Person('杨过');
console.log(p1.userName); //杨过
// console.log(userName); //Uncaught ReferenceError: userName is not defined

console.log(p1.userAge); //12
// console.log(userAge); //Uncaught ReferenceError: userAge is not defined
window.Person("段誉");
console.log(userName, window.userName); //段誉 段誉
console.log(userAge, window.userAge); //12 12

Person("乔峰");
console.log(userName, window.userName); //乔峰 乔峰
console.log(userAge, window.userAge); //12 12

console.log(window.name);

function Cat(str) {
	this.name = str;
	//没有使用var关键字定义的变量是全局变量
	hobby = "羽毛球"; //全局变量(全局变量是属于window对象的属性)
}

var catA = new Cat('Tom');
console.log(catA.name);//Tom
console.log(name);

console.log(catA.hobby);//undefined
console.log(hobby, window.hobby);//羽毛球 羽毛球
</script>
</head>
<body style="background-color: #CCE8CF;">
<h2>javaScript中this以及window对象和window对象的name属性</h2>
<div id="div1" style="background-color: Wheat; height: 200px;">
</div>
</body>
</html>

The knowledge points of this and the name attribute of the window object and the window object in javaScript, it is best for you to write it yourself, test it, and understand it yourself.

This and the name attribute of the window object and the window object in javaScript

Guess you like