How to print palindromic numbers on the console!

[AlfieSDK]

Hi!

I'm trying to make the console print only palindromic 4 digit numbers, but i can't find a way. I do know how to do it with one number in particular like "2002", where i use :
String palindrome = "2002";

if (palindrome.charAt(0) == palindrome.charAt(3)
&& palindrome.charAt(1) == palindrome.charAt(2)) {
System.out.println("is a palindrome");
}

But i can't do it like that, because i'm using a increment cycle, so it's an "int" and not a String like the case above....
How could i compare different characters on an "int"?
or maybe i got it all wrong.
I'm kinda lost....

Thank you!

[Norm]

How could i compare different characters on an "int"

There are no characters in an int. An int holds a numberic value.
You can convert an int to a String by a method in the Integer class.
Or the quick and dirty way: String intStr = "" + intVar;

[AlfieSDK]

Thank you Norm, i will try it out.
if not, then i'll come back.

[sunde887]

Also, what makes a number(or word) a palindrome? Think about this and see if there is a method in the string(or stringXxx) class to accomplish this.

I leave it intentionally vague, when/if you realize what I'm hinting at it becomes incredibly simple to find if a number(or word) is a palindrome. You will also be able to test numbers(or words) where the length is x and x is an unknown.

[Norm]

Do you talk of finding a palindrome for int values? If you convert the int to a String, what base do you use?
Or do you look at the int value in hex? or binary?

[AlfieSDK]

I think I did it....
Thank you guys!
I just needed to print 4 digit palindromes... :D
public class capicuaParcial {

public static void main(String[] args) {

for (int contador = 1000; contador < 10000; contador++) {
System.out.println(contador);
String numerosEnLetras = contador + "";
if (numerosEnLetras.charAt(0) == numerosEnLetras.charAt(3)
&& numerosEnLetras.charAt(1) == numerosEnLetras.charAt(2)) {
System.out.println(contador+" es Capicua");
}
}

}
}

[sunde887]

Glad you solved it.

As to my approach I was hinting at(in case you need to find out if less than or more than a 4 digit(letter) word is palindrome) was this.

A word, or number is a palindrome if it can be spelled the same forwards and backwards(the key word here is backwords)

Palindromes:
ale
1331
16461

So if you can turn the number into a string, you can simply reverse it and compare it to the original.

You can do it the naive way, and loop through the string backwards constructing it in a stringbuilder. The smart, and simpler way would be to simply reverse it with a method call, then compare them with equals.