Java Program to check if a String is Palindrome or not

In this post we will go through the java string program to check if a String is Palindrome or not. We will also run the examples and corresponding output.

A string is called a palindrome if the reverse of that string is same as the original string. For example: level, madam, etc.

Problem :

simple example of the problem  –

Example 1:

Input :  str = “abba” 

Output :  Yes, the given string is a palindrome.

Example 2:

Input :  str = “Hello” 

Output :  No, this string is not a palindrome.

Explanation:

For the string “abba“, you can see that if you read the string from backwards or forward, it reads the same. So, this string is a palindrome.

But for the string “Hello“, it’s not a palindrome as it doesn’t read the same for the backwards and forward.

Algorithm:

  • take or input a String.
  • take a variable “rev” to store reverse value of string.
  • get the length of string
  • Take a i loop start it from i=s.length()-1 to i>=0
  • .Then get each characterusing charAt() method and store it in rev variable.
  • if rev variable is equal to string then print “String is palindrome”.
  • Else print “String is not palindrome”.
class Main{
public static void main(String[]args){
String s ="madam";
String rev="";
int len=s.length();
for(int i=len-1;i>=0;i--){
rev=rev+s.charAt(i);
}
if(s.equals(rev)){
System.out.println(s+" is palindrome");
}
else{
System.out.println(s+ " is not palindrome")
}
}
}

Output:

madam is palindrome

other java practice programs:

Java Program to Check a Number is Palindrome or Not

Java Program to Get Input from User

Java program to reverse a string

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