老师帮忙看下代码及是否有需要修改的地方

来源：3-31 编程练习

lcy_18

2020-08-08 13:18:53

<!DOCTYPE html>
<html>
<head>
    <meta charset="UTF-8">
    <title>首字母变大写</title>
</head>
<body>
<script>
    //补充代码
    var str="all time is no time when it is past";
    function big(str){
    var arr=str.split(" "),newStr=[];
    for (var i=0;i<arr.length;i++) {
      var word=arr[i];
      newStr+=word.charAt(0).toUpperCase()+word.substr(1)+" ";
    }
  return newStr;
    }
    var a=big(str);
    document.write(a);
</script>
</body>
</html>