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@@ -0,0 +1,68 @@
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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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+ <!--
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+ JS数据类型：
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+ 基本数据类型：
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+ Null Undefined Number Boolean String
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+ 引用数据类型
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+ Object Array Function
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+ -->
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+ <script>
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+ let obj = {
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+ name: 'Lucy',
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+ age: 10
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+ }
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+ let arr = [1,2,3,4,5,6];
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+ function fn1() {
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+ return "哈哈哈"
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+ }
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+ // 1.typeof
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+ // 能判断出： undefined string number boolean function
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+ // 不能判断出： null object array
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+ // console.log(typeof null); // object
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+ // console.log(typeof undefined); // undefined
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+ // console.log(typeof '1'); // string
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+ // console.log(typeof 3); // number
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+ // console.log(typeof true);// boolean
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+ // console.log(typeof obj); // object
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+ // console.log(typeof arr); // object
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+ // console.log(typeof fn1); // function
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+
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+ // 2.obj(任意值) instanceof Object类型
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+ // console.log(obj instanceof Object); // true
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+ // console.log(arr instanceof Array); // true
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+ // console.log(fn1 instanceof Function); // true
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+
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+
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+ // 3.Object.prototype.toString.call()
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+ // console.log(Object.prototype.toString.call(1));// [Object Number]
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+ // console.log(Object.prototype.toString.call("21"));// [Object String]
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+ // console.log(Object.prototype.toString.call(true));// [Object Boolean]
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+ // console.log(Object.prototype.toString.call(undefined));// [Object Undefined]
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+ // console.log(Object.prototype.toString.call(null));// [Object Null]
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+ // console.log(Object.prototype.toString.call(fn1));// [Object Function]
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+ // console.log(Object.prototype.toString.call(arr));// [Object Array]
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+ // console.log(Object.prototype.toString.call(obj));// [Object Object]
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+
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+ // 4.constructor
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+ // 不判断null和undefined
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+ console.log(false.constructor === Boolean); // true
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+ console.log((1).constructor === Number); // true
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+ console.log('2121'.constructor === String); // true
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+ console.log(obj.constructor === Object); //true
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+ console.log(arr.constructor === Array); //true
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+ console.log(fn1.constructor === Function); //true
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+ // console.log(null.constructor === null); //报错
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+ // console.log(undefined.constructor === undefined); // 报错
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+
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+
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+
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+ </script>
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+</body>
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+</html>
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