console 命令行工具 X clear

console

var str ="Rome was not built in a day";
var arr =str.split("");//去掉所有的空格
document.write("该字符串的长度："+arr.length);

<!DOCTYPE html> 
<html>
<head>
    <meta charset="utf-8" />
    <title></title>
    <script>
    </script>
</head>
<body>
</body>
</html>