SOURCE

console 命令行工具 X clear

                    
>
console
function toDecimalMark(num) {
  if(num === '' || num === null || num === undefined || typeof num !== 'number') return false;
  let numStr = num.toString();
  let arr = numStr.split('.');
  let intPart = arr[0];
  let decimalPart = arr.length > 1 ? '.' + arr[1] : '';
  if (intPart.length <= 3) {
    return intPart + decimalPart;
  } else {
    let reg = /(\d)(?=(\d{3})+$)/g;
    return intPart.replace(reg, '$1,') + decimalPart;
  }
}

console.log(toDecimalMark(1234.5886)); // 1,234.56

console.log(toDecimalMark(-1234)); // 1,234.56
console.log(toDecimalMark(12345678.90)); // 12,345,678.90
function toDecimalMark(num) {
  if(num === '' || num === null || num === undefined || typeof num !== 'number') return false;
  let numStr = num.toString();
  let arr = numStr.split('.');
  let intPart = arr[0];
  let decimalPart = arr.length > 1 ? '.' + arr[1] : '';
  if (intPart.length <= 3) {
    return intPart + decimalPart;
  } else {
    let reg = /(\d)(?=(\d{3})+$)/g;
    return intPart.replace(reg, '$1,') + decimalPart;
  }
}

console.log(toDecimalMark(1234.56)); // 1,234.56

console.log(toDecimalMark(-1234)); // 1,234.56
console.log(toDecimalMark(12345678.90)); // 12,345,678.90