# Validate PIN code

Validate PIN code programming exercise.

Pin code validation emergency!!! Coders needed!
ATM machines allow 4 or 6 digit PIN codes and PIN codes cannot contain anything but exactly 4 digits or exactly 6 digits.

Write a function that returns true if a given string is possible PIN code or false if not.

`Example:"1234" => true"123456" => true"12ab" => false`

You can scroll down for the solution. Or not. It is a good solution so you should scroll down. Just saying. Came on, PLEASE 🙂 🙂

```   public static bool ValidatePin(string pin)
{
//again there is many ways do solve this coding problem
//I just want to introduce the TryParse() function
//So first we check if the length of the string is 4 or 6
//with the ||(OR) operator.
//And then, about TryParse():
//this function does not one but two things.
//It is not very usual for functions to do that.
//The way it does it, is with this "out" keyword.
//You can google it :)
//1) converts string to a number
//2) returns true or false for the success of the operation
//The rest is simple
//if the (the Length of the string) Length=4 or Length=6
//and if the pin is successfully converted to a number
//we return true. Else we return false.
if (pin.Length==4 || pin.Length ==6)
{
int r;
if (int.TryParse(pin, out r)) return true;
else  return false;
}
else
{
return false;
}
}```