Java program to check for Anagram

An anagram of a string is another string that contains the same characters, only the order of characters can be different. For example, “abcd” and “dabc” are an anagram of each other.

We are given two strings, we need to check if strings are Anagram.

Examples:

Input : "anagram", "nagaram"
Output : yes

Input : "mat", "fat"
Output : no

Method 1: Check if Two Strings Are Anagram using Array

import java.util.Arrays;

public class Main {

    public static boolean checkAnagram(String s1, String s2)
    {
        // Remove all the white space
        s1 = s1.replaceAll("\\s", "");
        s2 = s2.replaceAll("\\s", "");

        // Check if both length matches
        if(s1.length() != s2.length())
            return false;
        else
        {
            // Convert both Strings into lower case and into Character Array
            char[] arr1 = s1.toLowerCase().toCharArray();
            char[] arr2 = s2.toLowerCase().toCharArray();

            // Sort both Character Array
            Arrays.sort(arr1);
            Arrays.sort(arr2);

            // Check if both arrays are equal
            return (Arrays.equals(arr1, arr2));
        }
    }
    public static void main(String []args)
    {
        System.out.println(checkAnagram("anagram","nagaram"));
        System.out.println(checkAnagram("mat","fat"));
    }
}

Console Output:

true
false

Method 2: Check Anagram using HashMap

import java.util.HashMap;

public class Main {

    public static boolean checkAnagram(String s1, String s2)
    {
        if (s1.length() != s2.length())
            return false;
        HashMap<Character, Integer> map = new HashMap<Character, Integer>();
        for (int i = 0; i < s1.length(); i++)
        {
            char c = s1.charAt(i);
            if (map.containsKey(c))
                map.put(c, map.get(c) + 1);
            else
                map.put(c, 1);
        }
        for (int i = 0; i < s2.length(); i++)
        {
            char c = s2.charAt(i);
            if (map.containsKey(c))
            {
                if (map.get(c) == 1)
                    map.remove(c);
                else
                    map.put(c, map.get(c) - 1);
            } else
                return false;
        }
        if (map.size() > 0)
            return false;
        return true;
    }

    public static void main(String []args)
    {
        System.out.println(checkAnagram("anagram","nagaram"));
        System.out.println(checkAnagram("mat","fat"));
    }
}

Console Output:

true
false










Method 3: Anagram Program using XOR

public class Main {

    public static boolean checkAnagram(String s1, String s2)
    {
        // Remove all the white space, convert 
        // to lower case & character array
        char[] arr1 = s1.replaceAll("\\s", "")
                .toLowerCase().toCharArray();
        char[] arr2 = s2.replaceAll("\\s", "")
                .toLowerCase().toCharArray();
        if (arr1.length != arr2.length)
            return false;

        int xor = 0;

        for (int i = 0; i < arr1.length; i++)
        {
            xor ^= arr1[i] ^ arr2[i];
        }

        return xor == 0? true: false;
    }

    public static void main(String []args)
    {
        System.out.println(checkAnagram("anagram","nagaram"));
        System.out.println(checkAnagram("mat","fat"));
    }
}

Console Output:

true
false