JS的数据类型转换 

<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>Title</title>
    <script>
        var num1 ="3.14"
        var ret1 = parseFloat(num1) // #将字符串转换为数字
        console.log(ret1,typeof ret1) // 3.14 'number'

        var num2 ="100件"
        var ret2 = parseInt(num2)
        console.log(ret2,typeof ret2) // 100 'number' #将字符串转换为数字

        var num3 ="第100件"
        var ret3 = parseInt(num3)
        console.log(ret3,typeof ret3) // NaN 'number' #将字符串转换为数字

        var num4 = 3.14
        var ret4 = num4.toString() // 3.14 strings #将数字转换为字符串
        console.log(ret4,typeof ret4)

    </script>
</head>
<body>
<h1>welcome to JS!</h1>
</body>
</html>

 

posted @ 2022-06-01 20:21  呼长喜  阅读(59)  评论(0)    收藏  举报