46 lines
1.2 KiB
HTML
46 lines
1.2 KiB
HTML
<!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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<script>
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var lanzi="苹果"
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// var lanzi ---第一步 变量声明 问系统要个篮子 用来放东西
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// lanzi="苹果" --第二步 赋值 把苹果放到篮子里
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document.write('明世隐')
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var a=1,b=2,c=3,d=4,e; // 声明多个变量
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document.write(a,b,c,d,e)
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var no=1;
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var num=no
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num=3;
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console.log(no,num)
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var obj={name:'蔡文姬',age:20}
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var obj1=obj
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obj1.name='明世隐'
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console.log(obj)
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console.log(obj1)
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//检测数据类型
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console.log(typeof "king")
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console.log(typeof obj) //object
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console.log(typeof [1,2,3]) //array--> object
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console.log(typeof function(){}) //object
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console.log(Number('2AAAAA')) //NAN
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console.log(Number('2')) //2
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console.log('2aaaaa'+4) //2aaaaa4
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console.log("4"+4) //44
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console.log("4"-4) //0
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console.log(true+5) //6
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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> |