lovecoding
/
W250511


			
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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>
        console.log(Math.PI);

        var num = 10.1;
        // 四舍五入
        console.log(Math.round(num));
        // 向下取整
        console.log(Math.floor(num));
        // 向上取整
        console.log(Math.ceil(num));


        var num2 = "8.2";
        // 字符串拼接
        console.log(num2 + 2);

        // 字符串转数字 只能转换成整型 取整数部分
        num2 = parseInt(num2)
        console.log(num2 + 2);

        var num3 = "8.2";
        num3 = parseFloat(num3);
        console.log(num3 + 2);
    </script>
</body>
</html>