How do I stop the loop when entering "0" in java?

Question

0.00/5 (No votes)

See more:

I want to make a program that well tell me what ever the user input is, it should tell me if it is either a palindrome or not. When user enters 0, I want it to exit out of the loop. Please help me do that! Thank you :D

What I have tried:

import java.util.Scanner;
class Palindrome
{
     public static void main(String args[])
     {
		 Scanner in = new Scanner(System.in);
		 
		 boolean isPalindrome = true;
		  
		  while (isPalindrome)
		  {
			  String reverseString="";
			  Scanner scanner = new Scanner(System.in);
			  
			  System.out.println("Enter a positive integer (0 to quit):");
			  String inputString = scanner.nextLine();
			  
			  int length = inputString.length();
			  
			  int i = length-1;
			  while ( i >= 0)
			  {
				  reverseString = reverseString + inputString.charAt(i);
				  i--;
			  }
			  
			  if (inputString.equals(reverseString))
			  System.out.println(inputString + " is a palindrome.");
			  else
			  System.out.println(inputString + " Input string is not a palindrome.");
			  
		  }
	  }
}

Posted 14-Oct-19 9:50am

LillyLeaf

Updated 14-Oct-19 10:19am

Add a Solution

Comments

Mohibur Rashid 14-Oct-19 16:21pm

is
Madam a palindrome?

LillyLeaf 14-Oct-19 16:53pm

yes

Mohibur Rashid 15-Oct-19 18:25pm

In this case, you will have to handle case.

1 solution

Add a Solution

Add your solution here

Treat my content as plain text, not as HTML

Preview 0

…

Existing Members

Sign in to your account

...or Join us

Download, Vote, Comment, Publish.

Your Email
Password
Forgot your password?

Your Email
This email is in use. Do you need your password?
Optional Password

I have read and agree to the Terms of Service and Privacy Policy
Please subscribe me to the CodeProject newsletters

When answering a question please:

Read the question carefully.
Understand that English isn't everyone's first language so be lenient of bad spelling and grammar.
If a question is poorly phrased then either ask for clarification, ignore it, or edit the question and fix the problem. Insults are not welcome.
Don't tell someone to read the manual. Chances are they have and don't get it. Provide an answer or move on to the next question.

Let's work to help developers, not make them feel stupid.

This content, along with any associated source code and files, is licensed under The Code Project Open License (CPOL)

Mohibur Rashid · Accepted Answer · 2019-10-14T10:19:00

Solution:

if(inputString.compareTo("0") == 0) 
  return;
// or
  break;

I know you are in the process of learning. Let me explain why the following is the worst way of writing java

BAD CODE

while ( i > 0) {
    reverseString = reverseString + inputString.charAt(i);
    i--;
}

Why?
By default java concat string using StringBuilder class(Except some literal value cases). so, if you write

String x = a + b;

Java will process this as

StringBuilder temp_var = new StringBuilder();
temp_var.add(a);
temp_var.add(b);
x = temp_var.toString();

This look clean on a string that is written outside of a loop. But what would happen when you use this inside a loop? It will create object for every operation.