In this program, we are going to share a Java Program to find duplicate Characters in a String. If you are a Java beginner and want to start learning the Java programming, then keep your close attention in this tutorial as I am going to share how to write a Java Program to find duplicate Characters in a String with the output.
Copy the below Java program and execute it with the help of Javac compiler. At the end of this program, We have shared the output of this program.
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 | import java.util.HashMap; import java.util.Map; import java.util.Set; public class Details { public void countDupChars(String str){ Map<Character, Integer> map = new HashMap<Character, Integer>(); char[] chars = str.toCharArray(); for(Character ch:chars){ if(map.containsKey(ch)){ map.put(ch, map.get(ch)+1); } else { map.put(ch, 1); } } Set<Character> keys = map.keySet(); for(Character ch:keys){ if(map.get(ch) > 1){ System.out.println("Char "+ch+" "+map.get(ch)); } } } public static void main(String a[]){ Details obj = new Details(); System.out.println("String: freewebmentor.com"); System.out.println("-------------------------"); obj.countDupChars("freewebmentor.com"); } } |
String: freewebmentor.com
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Char e 4
Char r 2
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