JS使用正则去除字符串最后的逗号

var s = "1,2,3,4,5,"
s=s.substring(0,s.length-1)
alert(s);

var str="a,b,c,d,"
var reg=/,$/gi;
str=str.replace(reg,"");
alert(str);

<script type="text/javascript">
//删除指定索引位置的字符，索引无效将不删除任何字符
String.prototype.deleteCharAt=function(sIndex){
if(sIndex<0 || sIndex>=this.length){
return this.valueOf();
}else if(sIndex==0){
return this.substring(1,this.length);
}else if(sIndex==this.length-1){
return this.substring(0,this.length-1);
}else{
return this.substring(0,sIndex)+this.substring(sIndex+1);
}
}
//上面的函数一定要放上面，否则不起作用
var s = "1,2,3,4,5,";
var index = s.toString().lastIndexOf(',');
var s=s.deleteCharAt(index);
alert(s);
</script>

s=s.ToString().RTrim(',')

s=s.TrimEnd(',')
//如果要删除"5,"，则需要这么写
char[]MyChar={'5',','};
s=s.TrimEnd(MyChar);
//s="1,2,3,4"

string.TrimEnd().Remove(string.Length - 2, 1)
string.Remove()