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@@ -0,0 +1,47 @@
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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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+ var date = new Date();
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+ var arr = new Array();
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+ var obj = new Object();
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+ var x = new Number();
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+ var y = new String();
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+ var z = new Boolean();
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+ console.log(x,y,z);
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+
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+ //1.Number.isFinite() 判断一个数是否是有限数
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+ console.log(Number.isFinite(100)); // true
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+ console.log(Number.isFinite(100 / 0)); //false
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+ console.log(Number.isFinite(Infinity)); // false
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+ console.log(Number.isFinite(-Infinity)); //false
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+
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+ //2.Number.isNaN() 判断是不是非法数字
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+ console.log(Number.isNaN(123)); // false
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+
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+ // 3.Number.parseInt() 将字符串转换为整数
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+ console.log(Number.parseInt("3.14"));
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+
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+ // 4.Number.parseFloat() 将字符串转换为浮点数
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+ console.log(Number.parseFloat("3.14"));
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+
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+ // 5.Number.isInteger() 判断当前值是否是整数
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+ console.log(Number.isInteger(5.4));
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+ console.log(Number.isInteger(5));
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+
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+ // 6.Math.trunc() 抹平小数 返回整数
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+ console.log(Math.trunc(6.3));
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+
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+ // 7.Math.sign() 传入的值 是正数,负数还是0
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+ console.log(Math.sign(199)); //1
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+ console.log(Math.sign(-199)); //-1
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+ console.log(Math.sign(0));//0
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+
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+ </script>
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+</body>
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+</html>
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