What is an anagram in Java?

In this section, we will discuss what is anagram in Java and how to check if the given string is an anagram or not. The anagram Java program is frequently asked in Java interviews.

Anagram

The dictionary meaning of the word anagram is a word or phrase formed by rearranging the letters.

Two strings are said to be anagrams if they make a meaningful word by rearranging or shuffling the letters of the string. In other words, we can say that two strings are anagrams if they contain the same characters but in a different order. Note that a letter has to be used only once.

Example of Anagram

There are several anagram words some of them are:

LISTEN - > SILENT

HEART - > EARTH

LIVES - > ELVIS

KEEP -> PEEK

TABLE - >BLEAT

How to check two strings are anagram or not?

Read or initialize two strings str1 and str2.
Find the length of both the strings.
Compare the length of the strings.
1. If length is not equal, print strings are not an anagram.
2. Else, do the following:
  1. Convert the string into a character array.
  2. Sort both the arrays by using the sort() method.
  3. After sorting, compare the strings by using the equals() method. Store the value in a Boolean variable (status) returned by the equals() method.
3. Pass the variable in the if statement. If it returns true, the given strings are anagram. Else, not an anagram.

Let's implement the above steps in a Java program.

Java Anagram Program

There is various way to find anagram string but, in this section, we will focus on the following three ways.

Using Arrays Class
Using for Loop
Using StringBuilder Class

Using Arrays Class

In the following program, we have used to methods String.sort() and equals() method to check if the two strings are anagram or not.

AnagramExample1.java

import java.util.Arrays;  
public class AnagramStringExample1
{  
//function that checks if the strings are anagram or not    
static void isAnagram(String str1, String str2) 
{  
//removes white spaces from string 1
String s1 = str1.replaceAll("\\s", "");  
//removes white spaces from string 2
String s2 = str2.replaceAll("\\s", "");  
boolean status = true;  
//checks the length of both the strings are equal or not
if (s1.length() != s2.length()) 
{  
//if length of strings is not equal status returns false    
status = false;  
} 
//executes if lengths of strings are equal
else 
{  
//first converts the string 1 in lower case and then converts the string into a character array    
//final string stores in arrayS1
char[] arrayS1 = s1.toLowerCase().toCharArray();  
//first converts the string 2 in lower case and then converts the string into a character array    
//final string stores in arrayS2
char[] arrayS2 = s2.toLowerCase().toCharArray();  
//sorts the character array arrayS1
Arrays.sort(arrayS1);  
//sorts the character array arrayS2
Arrays.sort(arrayS2);  
//compares the strings
status = Arrays.equals(arrayS1, arrayS2);  
}  
if (status) 
{  
//prints if status returns true    
System.out.println(s1 + " and " + s2 + " are anagrams");  
} 
else 
{  
//prints if status returns false    
System.out.println(s1 + " and " + s2 + " are not anagrams");  
}  
}  
//driver code
public static void main(String args[]) 
{  
//calling function    
isAnagram("HEART", "EARTH");  
isAnagram("TRIANGLE", "INTEGRAL");  
isAnagram("TOSS", "SHOT"); 
}  
}  

Output:

HEART and EARTH are anagrams
TRIANGLE and INTEGRAL are anagrams
TOSS and SHOT are not anagrams

Using for Loop

AnagramExample2.java

public class AnagramExample2
{
//function checks if the strings are anagram or not    
public static boolean isAnagram(String str1, String str2) 
{
//comparing length    
if (str1.length() != str2.length()) 
{
//returns false if the strings are not equal in length    
return false;
}
//converts string into character array
char[] chars = str1.toCharArray();
//loop iterates over the array
for (char c : chars) 
{
//finds the index    
int index = str2.indexOf(c);
if (index != -1) 
{
//the substring() method returns a new string that is a substring of this string
str2 = str2.substring(0, index) + str2.substring(index + 1, str2.length());
} 
else 
{
return false;
}
}
return str2.isEmpty();
}
//driver code
public static void main(String args[]) 
{  
//calling function    
System.out.println(isAnagram("HEART", "EARTH"));  
System.out.println(isAnagram("TRIANGLE", "INTEGRAL"));  
System.out.println(isAnagram("TOSS", "SHOT")); 
}  
}  

Output:

true
true
false

Using StringBuilder Class

AnagramExample3.java

public class AnagramExample3
{
//function checks if the strings are anagram or not    
public static boolean isAnagram(String str1, String str2) 
{
//converts string into character array    
char[] characters = str1.toCharArray();
StringBuilder sb = new StringBuilder(str2);
//loop iterates over the character array
for (char ch : characters) 
{
//finds index of the char    
int index = sb.indexOf("" + ch);
if (index != -1) 
{
//delete character at the specified index    
sb.deleteCharAt(index);
} 
else 
{
return false;
}
}
//finds length
return sb.length() == 0 ? true : false;
}
//driver code
public static void main(String args[]) 
{  
//calling function    
System.out.println(isAnagram("TABLE", "BLEAT"));  
System.out.println(isAnagram("TOSS", "SHOT")); 
}  
}  

Output: