将数字转换为字符串，每三位数字加逗号kdb/q

function addCommas(num) {
  var str = num.toString();
  var result = '';
  var count = 0;
  
  for (var i = str.length - 1; i >= 0; i--) {
    result = str.charAt(i) + result;
    count++;
    
    if (count % 3 === 0 && i !== 0) {
      result = ',' + result;
    }
  }
  
  return result;
}

var number = 1234567890;
var formattedNumber = addCommas(number);
console.log(formattedNumber); // 输出：1,234,567,890

def add_commas(num):
    str_num = str(num)
    result = ''
    count = 0
    
    for i in range(len(str_num) - 1, -1, -1):
        result = str_num[i] + result
        count += 1
        
        if count % 3 == 0 and i != 0:
            result = ',' + result
    
    return result

number = 1234567890
formatted_number = add_commas(number)
print(formatted_number)  # 输出：1,234,567,890