在JavaScript中为大于1000的数字添加逗号

var number = 10000;
var formattedNumber = number.toLocaleString();
console.log(formattedNumber); // 输出 "10,000"

var number = 10000;
var formattedNumber = number.toString().replace(/\B(?=(\d{3})+(?!\d))/g, ",");
console.log(formattedNumber); // 输出 "10,000"

function addCommas(number) {
  var parts = number.toString().split(".");
  parts[0] = parts[0].replace(/\B(?=(\d{3})+(?!\d))/g, ",");
  return parts.join(".");
}

var number = 10000;
var formattedNumber = addCommas(number);
console.log(formattedNumber); // 输出 "10,000"