convert number to zh_CN currency

convertCurrency.js

function convertCurrency(currencyDigits) {
  // Constants:
  var MAXIMUM_NUMBER = 99999999999.99;
  // Predefine the radix characters and currency symbols for output:
  var CN_ZERO = "零";
  var CN_ONE = "壹";
  var CN_TWO = "贰";
  var CN_THREE = "叁";
  var CN_FOUR = "肆";
  var CN_FIVE = "伍";
  var CN_SIX = "陆";
  var CN_SEVEN = "柒";
  var CN_EIGHT = "捌";
  var CN_NINE = "玖";
  var CN_TEN = "拾";
  var CN_HUNDRED = "佰";
  var CN_THOUSAND = "仟";
  var CN_TEN_THOUSAND = "万";
  var CN_HUNDRED_MILLION = "亿";
  var CN_SYMBOL = "人民币";
  var CN_DOLLAR = "元";
  var CN_TEN_CENT = "角";
  var CN_CENT = "分";
  var CN_INTEGER = "整";

  // Variables:
  var integral; // Represent integral part of digit number.
  var decimal; // Represent decimal part of digit number.
  var outputCharacters; // The output result.
  var parts;
  var digits, radices, bigRadices, decimals;
  var zeroCount;
  var i, p, d;
  var quotient, modulus;

  // Validate input string:
  currencyDigits = currencyDigits.toString();
  if (currencyDigits == "") {
    alert("请输入小写金额！");
    return "";
  }
  if (currencyDigits.match(/[^,.\d]/) != null) {
    alert("小写金额含有无效字符！");
    return "";
  }
  if ((currencyDigits).match(/^((\d{1,3}(,\d{3})*(.((\d{3},)*\d{1,3}))?)|(\d+(.\d+)?))$/) == null) {
    alert("小写金额的格式不正确！");
    return "";
  }

  // Normalize the format of input digits:
  currencyDigits = currencyDigits.replace(/,/g, ""); // Remove comma delimiters.
  currencyDigits = currencyDigits.replace(/^0+/, ""); // Trim zeros at the beginning.
  // Assert the number is not greater than the maximum number.
  if (Number(currencyDigits) > MAXIMUM_NUMBER) {
    alert("金额过大，应小于1000亿元！");
    return "";
  }

  // Process the coversion from currency digits to characters:
  // Separate integral and decimal parts before processing coversion:
  parts = currencyDigits.split(".");
  if (parts.length > 1) {
    integral = parts[0];
    decimal = parts[1];
    // Cut down redundant decimal digits that are after the second.
    decimal = decimal.substr(0, 2);
  } else {
    integral = parts[0];
    decimal = "";
  }
  // Prepare the characters corresponding to the digits:
  digits = new Array(CN_ZERO, CN_ONE, CN_TWO, CN_THREE, CN_FOUR, CN_FIVE, CN_SIX, CN_SEVEN, CN_EIGHT, CN_NINE);
  radices = new Array("", CN_TEN, CN_HUNDRED, CN_THOUSAND);
  bigRadices = new Array("", CN_TEN_THOUSAND, CN_HUNDRED_MILLION);
  decimals = new Array(CN_TEN_CENT, CN_CENT);
  // Start processing:
  outputCharacters = "";
  // Process integral part if it is larger than 0:
  if (Number(integral) > 0) {
    zeroCount = 0;
    for (i = 0; i < integral.length; i++) {
      p = integral.length - i - 1;
      d = integral.substr(i, 1);
      quotient = p / 4;
      modulus = p % 4;
      if (d == "0") {
        zeroCount++;
      } else {
        if (zeroCount > 0) {
          outputCharacters += digits[0];
        }
        zeroCount = 0;
        outputCharacters += digits[Number(d)] + radices[modulus];
      }
      if (modulus == 0 && zeroCount < 4) {
        outputCharacters += bigRadices[quotient];
        zeroCount = 0;
      }
    }
    outputCharacters += CN_DOLLAR;
  }
  // Process decimal part if there is:
  if (decimal != "") {
    for (i = 0; i < decimal.length; i++) {
      d = decimal.substr(i, 1);
      if (d != "0") {
        outputCharacters += digits[Number(d)] + decimals[i];
      }
    }
  }
  // Confirm and return the final output string:
  if (outputCharacters == "") {
    outputCharacters = CN_ZERO + CN_DOLLAR;
  }
  if (decimal == "") {
    outputCharacters += CN_INTEGER;
  }
  outputCharacters = CN_SYMBOL + outputCharacters;
  return outputCharacters;
}