JS implements the method of adding commas to every three digits of the number

This article describes the method of adding commas to every three digits of js. Share it 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"; //Automatically fill the two decimal points 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; //Connect one by one} count++; } str = newStr + (str + "00").substr((str + "00").indexOf("."),3); console.log(str) }}formatNum('13213.24'); //Output 13,213.34formatNum('132134.2'); //Output 132,134.20formatNum('132134'); //Output 132,134.00formatNum('132134.236'); //Output 132,134.23

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