console 命令行工具 X clear

console

function writeDocument(variable){
    document.write(variable+"<br/>");
}
str2="Rome was not built in a day";
var num=0;
var a=str2.match(/[a-zA-Z]/g)
for(i in a){
    num++
}
document.write(num+"<br/>");

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