Java Program to Find Duplicate Characters in a String

This java program finds duplicate characters in a string. In this program, we assign a string to a variable named "str" and this string is converted to character array using toCharArray() method and assigned to a variable "c". Then using nested for loop, we compare each character of char array to the other characters in array and if they match, we print that character.

Java Program to Find Duplicate Characters in a String

class FindDuplicateString{
 public static void main(String[] args){
  String str = "java";
  char[] c = str.toCharArray();
  System.out.print("Duplicate characters : ");
  for(int i=0; i<str.length(); i++){
   for(int j=i+1; j<str.length(); j++){
    if(c[i] == c[j]){
              System.out.print(c[i]+" ");         }
   }   
  }
 }
}

Output:

Duplicate characters : a