lovecoding
/
W0407


			
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							<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Document</title>
</head>
<body>
    <script>
        var x = new Number();
        console.log(x);
        // Number.isFinite() 判断一个值是否是有限数
        // console.log(Number.isFinite(1000))
        // console.log(Number.isFinite(100 / 0))
        // console.log(Number.isFinite(Math.PI))
        // console.log(Number.isFinite(-Infinity))


        // Number.isNaN() 判断一个值是否是非法数字
        // console.log(Number.isNaN(1000))
        // console.log(Number.isNaN(100 / 0))
        // console.log(Number.isNaN(Math.PI))
        // console.log(Number.isNaN(-Infinity))

        // Number.parseInt() 转成整数
        // console.log(Number.parseInt(1000))
        // console.log(Number.parseInt(100 / 0))
        // console.log(Number.parseInt(Math.PI))
        // console.log(Number.parseInt(-Infinity))


        // // Number.parseFloat() 转成小数
        // console.log(Number.parseFloat(1000))
        // console.log(Number.parseFloat(100 / 0))
        // console.log(Number.parseFloat(Math.PI))
        // console.log(Number.parseFloat(-Infinity))

        // Math.trunc() 抹平小数
        // console.log(Math.trunc(3.1414141))


        // Number.isInteger 判断传入的字符是否是整数
        // console.log(Number.isInteger(Math.PI))
        // console.log(Number.isInteger(555))
        // console.log(Number.isInteger(98.5))


        // Math.sign 判断传入的是正数还是负数
        console.log(Math.sign(Math.PI))
        console.log(Math.sign(555))
        console.log(Math.sign(98.5))
        console.log(Math.sign(-555))
        console.log(Math.sign(-98.5))
        console.log(Math.sign(0))
    </script>
</body>
</html>