Home > Article > Web Front-end > Can I use classes in JavaScript?
Class can be used in JavaScript; a class is a function, but instead of using the keyword function for initialization, use the keyword class and assign attributes in the constructor() method, each time the class object is initialized , the constructor() method will be called, and the syntax is "class className{constructor(){...}}".
The operating environment of this tutorial: Windows 10 system, JavaScript version 1.8.5, Dell G3 computer.
A class is a function, but instead of using the keyword function to initialize it, you use the keyword class and assign properties in the constructor() method.
Every time a class object is initialized, the constructor() method is called.
Note: Unlike function and other JavaScript declarations, class declarations are not hoisted (you must declare a class before you can use it).
Note: The syntax in the class must be written in "strict mode".
The syntax is:
class className {
// 类主体
}We use the class keyword to create a class. The class body is in a pair of braces {}. We can define the location of the class members in the braces {}. , such as a method or constructor.
Each class contains a special method constructor(), which is the constructor of the class. This method is used to create and initialize an object created by class.
The example is as follows:
<!DOCTYPE html>
<html>
<head>
<meta charset="utf-8">
<title>123</title>
</head>
<body>
<h2>JavaScript 类</h2>
<p>如何使用 JavaScript 类</p>
<p id="demo"></p>
<script>
class Runoob {
constructor(name, url) {
this.name = name;
this.url = url;
}
}
let site = new Runoob("好好学习", "//m.sbmmt.com");
document.getElementById("demo").innerHTML =
site.name + "：" + site.url;
</script>
</body>
</html>Output result:
javascript video tutorial 、webfrontend】
The above is the detailed content of Can I use classes in JavaScript?. For more information, please follow other related articles on the PHP Chinese website!