package com.java.interview.questions; import java.util.LinkedHashMap; import java.util.Map; public class FirstRepeatingCharacter { public static void main(String[] args) { LinkedHashMap hashMap = new LinkedHashMap(); String testWord = "Stress"; char[] listOfCharacters = testWord.toLowerCase().toCharArray(); for (Character c : listOfCharacters) { if(hashMap.containsKey(c)) { hashMap.put(c, hashMap.get(c) + 1); } else { hashMap.put(c,0); } } for (Map.Entry entry : hashMap.entrySet()) { if(entry.getValue() == 0) { System.out.println("The first non-repeating character is:" + entry.getKey()); break; } } } }