format number with commas and decimal javascript code example

Example 1: javascript format numbers with commas

function numberWithCommas(x) {
    return x.toString().replace(/\B(?=(\d{3})+(?!\d))/g, ",");
}

Example 2: format number with commas js

foramtNumber = (num,div=",")=>{
  return num.toString().replace(/\B(?=(\d{3})+(?!\d))/g, div);

}

Example 3: how to format an integer with a comma in javascript

x.toString().toLocaleString(); // x must be a number