Java tutorial
public class MainClass { public static void main(String[] args) { String input = null; try { String capitalized = capitalize(input); System.out.println(capitalized); } catch (NullPointerException e) { System.out.println(e.toString()); } } public static String capitalize(String s) throws NullPointerException { if (s == null) { throw new NullPointerException("Your passed a null argument"); } Character firstChar = s.charAt(0); String theRest = s.substring(1); return firstChar.toString().toUpperCase() + theRest; } }