js method to add commas to every three digits in numbers_javascript skills

The example in this article describes the js method of adding commas to every three digits in numbers. Share it with everyone for your reference. The specific implementation method is as follows:

function formatNum(str){
var newStr = "";
var count = 0;

if(str.indexOf(".")==-1){
   for(var i=str.length-1;i>=0;i--){
 if(count % 3 == 0 && count != 0){
   newStr = str.charAt(i) + "," + newStr;
 }else{
   newStr = str.charAt(i) + newStr;
 }
 count++;
   }
   str = newStr + ".00"; //自动补小数点后两位
   console.log(str)
}
else
{
   for(var i = str.indexOf(".")-1;i>=0;i--){
 if(count % 3 == 0 && count != 0){
   newStr = str.charAt(i) + "," + newStr;
 }else{
   newStr = str.charAt(i) + newStr; //逐个字符相接起来
 }
 count++;
   }
   str = newStr + (str + "00").substr((str + "00").indexOf("."),3);
   console.log(str)
 }
}

formatNum('13213.24'); //输出13,213.34
formatNum('132134.2');  //输出132,134.20
formatNum('132134');  //输出132,134.00
formatNum('132134.236');  //输出132,134.23

I hope this article will be helpful to everyone’s JavaScript programming design.