Write a java program to find weather a given string is a palindrome or not?

Answer 1

import java.io.*;

class StringPalindrome

{

static void main()throws IOException

{

InputStreamReader isr=new InputStreamReader(System.in);

BufferedReader br= new BufferedReader(isr);

System.out.println("Enter a word");

String input=br.readLine();

int x= input.length();

char ans;

String fin="";

for(int y=x-1; y>=0; y--)

{

ans=input.charAt(y);

fin=fin+ans;

}

System.out.println("The reverse is " + fin);

if(fin.equalsIgnoreCase(input))

{

System.out.println("Palindrome");

}

else

{

System.out.println("Not a palindrome");

}

}

}

Answer 2

//call this method inputing the string you want to test

private void palindromeTest(String input){

String output = """+input+"" "; output = output +

((getReverseString(input).equals(input)) ?

"is a palindrome" : "is not a palindrome");

System.out.println(output);

}

private String getReverseString(String input){

String revInput = "";

for(int i=input.length(); i>0; i--)

{

revInput= revInput + input.charAt(i-1);

System.out.println(revInput);

}//end i

return revInput;

}

Answer 3

StringBuilder sb = new StringBuilder("Palindrome goes here");

String bs = new String(sb.reverse().toString());

System.out.println(bs.equals(sb.toString()));

//I'm not writing the whole program, this should get you started. if output = true, then the string was a Palindrome, else it wasn't

Answer 4

Use a loop to check if the first and last characters in the string are the same, then check the second and second to last.

put this in any chass and it will return true or fasle for if the string passed is a palindrome.

public static boolean palindrome(String text){

for(int i = 0; i < text.length()-1; i++){

int lastChar = text.length()-1;

if(text.charAt(i)!=text.charAt(lastChar-i)){//if the characters are not the same, then it is not a palindrome.

return false;

}

}

return true;//if all the characters fit then it must be a palindrome

}

Answer 5

import java.io.*;

public class Palindrome {

public static void main(String [] args){

try{

BufferedReader object = new BufferedReader(

new InputStreamReader(System.in));

System.out.println("Enter number");

int num= Integer.parseInt(object.readLine());

int n = num;

int rev=0;

System.out.println("Number: ");

System.out.println(" "+ num);

for (int i=0; i<=num; i++){

int r=num%10;

num=num/10;

rev=rev*10+r;

i=0;

}

System.out.println("After reversing the number: "+ " ");

System.out.println(" "+ rev);

if(n == rev){

System.out.print("Number is palindrome!");

}

else{

System.out.println("Number is not palindrome!");

}

}

catch(Exception e){

System.out.println("Out of range!");

}

}

}

Answer 6

public static void main(String[] args) { UserInterface ui = new UserInterface(); Stack stack = new Stack(); Queue queue = new Queue(); String cleaned = new String(); boolean palindrome = true; ui.setString("Please give me a palindrome."); cleaned = ui.cleanString(ui.getString()); for (int i = 0; i < cleaned.length(); ++i) { stack.push(cleaned.charAt(i)); queue.enqueue(cleaned.charAt(i)); } while (!stack.isEmpty() && !queue.isEmpty()) { if (stack.pop() != queue.dequeue()) { palindrome = false; } } if (palindrome) { System.out.printf("%s is a palindrome!", ui.getString()); } else System.out.printf("%s is not a palindrome :(", ui.getString()); stack.dump(); queue.clear(); } public class Stack { public void push(char c) { c = Character.toUpperCase(c); Node oldNode = header; header = new Node(); header.setData(c); header.setNext(oldNode); } public char pop() { Node temp = new Node(); char data; if (isEmpty()) { System.out.printf("Stack Underflow (pop)\n"); System.exit(0); } temp = header; data = temp.getData(); header = header.getNext(); return data; } } public class Queue { public void enqueue(char c) { c = Character.toUpperCase(c); Node n = last; last = new Node(); last.setData(c); last.setNext(null); if (isEmpty()) { first = last; } else n.setNext(last); } public char dequeue() { char data; data = first.getData(); first = first.getNext(); return data; } } public String cleanString(String s) { return s.replaceAll("[^A-Za-z0-9]", ""); }

Answer 7

If you do not know how to program/code or how to program/code using the Java language, then you need to go on a course to learn these skills.

Once you have these skills you need to write some code that reverses the characters making up the number (or word) then compares each character in turn with the original. If all the character match, you have a palindrome.