63 lines
1.5 KiB
HTML
63 lines
1.5 KiB
HTML
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<!DOCTYPE html>
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<html lang="en">
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<head>
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<meta charset="UTF-8">
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<meta http-equiv="X-UA-Compatible" content="IE=edge">
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<meta name="viewport" content="width=device-width, initial-scale=1.0">
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<title>Document</title>
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<script>
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console.log(a)
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var a=9
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function a(){}
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// var num=2 //var 是js里面定义变量的关键字
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// console.log(num)
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// num=9
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// console.log(num)
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// const num1=2 // 常量是定义以后值不能改变的量 声明的话 用const关键字
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// // 使用常量的时候，初始值不能为空 初始值为空的常量没有意义
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// console.log(num1)
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// num1=8
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// console.log(num1)
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// var和let 都是用来声明变量的
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// var num=2
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// var num=8
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// console.log(num)
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console.log(num,"llo")
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let num=2
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// let num=8
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console.log(num)
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// let 不能在同一个块级作用域中重复声明
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for(var i=0;i<5;i++){
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let num=8
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console.log(num)
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}
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function f(){
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let num=5
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let name="a"
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function g(){
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let name="b"
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console.log(name)
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function c(){
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// let name="c"
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console.log(name)
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}
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c()
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}
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console.log(num)
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console.log(name)
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g()
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}
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f()
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</script>
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</head>
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<body>
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</body>
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</html>
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