处理字符串中逗号的js算法，3种（前端网备份）

<!DOCTYPE html>
<html>
<head>
<meta charset="utf-8">
<meta name="viewport" content="width=device-width, initial-scale=1.0">
<title>111</title>

</head>

<script src="js/jquery.min.js"></script>
<script type="text/javascript">
 var  devc='123,2345,45678,56789';
 var sum = 0;
 /*charCodeAt 获取逗号的编码*/
        for(var i=0;i<devc.length;i++){
            if(devc.charCodeAt(i) == ','.charCodeAt(0)){
                sum++
            }
        }
        console.log(sum) //3(求逗号的个数)

for(var i=0;i<devc.length;i++){
            if(devc.charAt(i) == ','){
                sum++
            }
        }
        console.log(sum)//3

var str=devc.split(',').length;
console.log(str) //4

              $.trim()是删除字符串开始和末尾的空格
                console.log(tem);

               console.log(typeof tem);
               console.log(date);
               console.log(typeof date);
               var tem1=$.trim(tem);
               var data9=$.trim(date);

</script>

</body>
</html>