38 lines
626 B
HTML
38 lines
626 B
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 name="viewport" content="width=device-width, initial-scale=1.0">
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<title>Document</title>
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</head>
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<body>
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<script>
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//js 弱类型
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//变量
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var a0
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var a1= "xxx"
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let b0
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let b1= "xxx"
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const c0= "xxx"//只能赋值
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//1.
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//在全局变量 var 声名的变量,是挂在window全局对象上的
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//在全局变量let 声名的变量,就是全局变量
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//2.
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//var可以重复声名
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//let const 不可以重复声名
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//3.
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//const声名的是常量 无法修改
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</script>
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</body>
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</html>
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