Taiwan National Identification Number Validator 台灣身分證驗證

tw_id_number_validator.js

function isValidIdNumber(str) {
  if(!/^[A-Z]\d{9}$/.test(str)) return false;

  var multiplier = [1, 9, 8, 7, 6, 5, 4, 3, 2, 1, 1];
  var map = {
    'A': 10, 'B': 11, 'C': 12, 'D': 13, 'E': 14, 'F': 15, 'G': 16, 'H': 17, 'I': 34,
    'J': 18, 'K': 19, 'L': 20, 'M': 21, 'N': 22, 'O': 35, 'P': 23, 'Q': 24, 'R': 25,
    'S': 26, 'T': 27, 'U': 28, 'V': 29, 'W': 32, 'X': 30, 'Y': 31, 'Z': 33
  };
  var decoder = function(id_number){
    return id_numbar.replace(/[A-Z]/, function(char){ return map[char]; });
  };
  var numbers = decoder(str).split(), sum = 0;

  for (var i = 0 ; i < 11 ; i++) {
    sum += numbers[i] * multiplier[i];
  }
  return sum % 10 == 0;
};