html从零开始9：javaScript简介，语句、标识符，变量，JavaScript引入到文件【搬代码】

搬代码2024-02-17 8:40

javaScript简介

javaScript语句、标识符

变量

html 复制代码

var num =10;
var就是固定声明,num就是变量名，10就是变量；

html 复制代码

<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta http-equiv="X-UA-Compatible" content="IE=edge">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title></title>
</head>
<body>

    <script>
        var num = 10;
        console.log(num)
    </script>
</body>
</html>

JavaScript引入到文件

嵌入到html文件中

html 复制代码

<body>

    <script>
        var num = 10;
        console.log(num)
    </script>
</body>

引入本地独立js文件中

html 复制代码

<body>

    <script src="./hellojs.js"></script>
</body>

javascript 复制代码

var age = 20;
console.log(age)

引入网络来源文件

html 复制代码

<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta http-equiv="X-UA-Compatible" content="IE=edge">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title></title>
    /*引入外部文件*/
    <script src="https://cdn.bootcdn.net/ajax/libs/jquery/3.6.0/jquery.min.js"></script>
</head>
<body>

   
    
</body>
</html>