Java: Check if a given string has all unique characters

Java Basic: Exercise-141 with Solution

Write a Java program to check if a given string has all distinct characters.

Pictorial Presentation:

Sample Solution:

Java Code:

import java.util.*;
public  class Solution {
    /**
     * @param str: a string
     * @return: a boolean
     */
    public static boolean is_Unique_str(String str) {
        // Convert the input string to a character array
        char[] chars = str.toCharArray();
        
        // Sort the character array in lexicographical order
        Arrays.sort(chars);
        
        // Check for repeated characters in the sorted array
        for (int i = 1; i < chars.length; ++i) {
            if (chars[i] == chars[i-1]) {
                return false;
            }
        }
        
        // If no repeated characters are found, the string is considered to have all unique characters
        return true;
    }
    
    public static void main(String[] args) {
        // Test case: Check if the string "xyyz" has all unique characters
        // Note: You can change the value of the 'str' variable for different input strings.
        String str = "xyyz";
        
        // Print the original string
        System.out.println("Original String : " + str);
        
        // Check if the string has all unique characters and print the result
        System.out.println("String has all unique characters: " + is_Unique_str(str));
    }   
}

Sample Output:

Original String : xyyz
String has all unique characters: false

Flowchart:

Java Code Editor:

Previous: Write a Java program to get the index of the first number and the last number of a subarray where the sum of numbers is zero from a given array of integers.
Next: Write a Java program to check if two given strings are anagrams or not.