console 命令行工具 X clear

console

var str = "Rome was not built in a day";
arr = str.replace(/\s/g);//去掉所有的空格
var sum = 0;
for(var i of str){
    sum++;
}
document.write(sum);

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