Question

Possible Duplicate:
How do I compare strings in Java?

(This may be a duplicate, I was not aware of .equals. My apologies.)

I was messing around in Java today when I decided to make a 4 character string generator. I have the program generate every possible combination of characters that I defined. This isn’t for a project, I just wanted to see if this was possible. My problem lies with the string checking. I’ll post the code first.

String text = "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz";
char[] chars = text.toCharArray();
String name = "Mike";
String pass;

outerLoop:
for (int a = 0; a < chars.length; a ++) {
    for (int b = 26; b < chars.length; b++) {
        for (int c = 26; c < chars.length; c++) {
            for (int d = 26; d < chars.length; d++) {
                pass = chars[a]+""+chars[b]+""+chars[c]+""+chars[d];
                System.out.println(pass);
                if (pass == name){
                    System.out.print("password");
                    break outerLoop;
                }
            }
        }
    }
}

The nested if will check if pass is equal to Mike. If it is, then it prints password and will break the for loop.

• Is pass = chars[a]... the correct way to do this? When I tested it without the if, I had it print out pass and it printed all of the combinations correctly. It did print Mike, but it did not catch in the if.
• I also changed the nested for loops so they start with the lower case because the program was taking a while to run when I made minor changes.

Answer 1

            if (pass == name){

should be

            if (pass.equals(name)){

use String.equals() method to check string equality. == operator simply checks if two reference variables refer to the same object. equals() method checks if two strings are meaningfully equal.