Snippet to Validate a Pin code or Password for repetition, matched length and weak pin codes ( nested integers)

validatePin.js

/**
   * 
   * Author: aramics
   * Function to validate pin code or password
   * Return boolean;
   * @param pin string to validate as pin e.g "9358"
   * @param norepeat  boolean: check if pin contain repetitive number
   * @param noserial boolean: check if pin contain nexted integer e.g 12 or 34
   * @param pinLength int: length of the pin
   * validatePin("9358",4,false,true)
   */
function  validatePin(pin,pinLength=4,norepeat=true,noserial=true){
    if (pin == null || pin.length != pinLength)
        return false;
    var count = Array(10);
    for (var i = 0; i < pin.length; i++) {
        var c = pin.charAt(i);
        c = parseInt(c);
        if(isNaN(c))
            return false;
        if(norepeat && count.indexOf(c)>-1){ //duplicate number
          return false;
        }
        if(noserial && c+1 == pin.charAt(i+1)) //increment e.g 1234
          return false
        count[i] = c;
    }

    return true;
  }