JS截字符串处理数字，汉字，英文问题

<script>
    function suolve( str,sub_length ){
		var temp1 = str.replace(/[^\x00-\xff]/g,"**");//精髓
		var temp2 = temp1.substring(0,sub_length);
		//找出有多少个*
		var x_length = temp2.split("\*").length - 1 ;
		var hanzi_num = x_length /2 ;
		sub_length = sub_length - hanzi_num ;//实际需要sub的长度是总长度-汉字长度
		var res = str.substring(0,sub_length);
		if(sub_length < str.length ){
		   var end =res+"……" ;
		}else{
		   var end = res ;
		}
		   return end ;
	}
    var str1="1111哇咔咔咔";
    var str2="11哇11哇咔咔咔"
    console.log(suolve(str1,6));
    console.log(suolve(str2,6));
</script>