Java: if/else statement in infinite loop not working

Question

I'm trying to figure out why my function isn't working as it should. The code is fairly basic and self explanatory. Here is the function:

public static void Greet(){
    System.out.println("Hello, what is your name? ");
    name = scan.nextLine();
    do{
        System.out.println("Would you like to order some coffee, " + name + "? (y/n) ");
        input = scan.nextLine();
        if(input == "y"){
            System.out.println("Great! Let's get started.");
            break;
        }
        else if(input == "n"){
            System.out.println("Come back next time, " + name + ".");
            System.exit(0);
        }
        else{
            System.out.println("Invalid response. Try again.");
        }
    }
    while(true);
}

Basically, regardless of what I enter as "input" on line 5, the function will treat it as if I hadn't entered a 'y' or 'n', it just constantly loops the while(true) and printing "Invalid response. Try again." I have no idea why my if/else statements aren't working correctly. Any help would be appreciated, thanks!

I have a break on line 9, but that isn't the problem. The problem is regardless of what I input, it consistently loops to the final 'else' statement. — Jasper Squire, Apr 24 '15 at 05:20
I replaced `input == "y"` and `input == "n"` with `"y".equalsIgnoreCase(input)` and `"n".equalsIgnoreCase(input)` and it seems to work fine for me — MadProgrammer, Apr 24 '15 at 05:27
@JasperSquire Before asking questions first you need to read Java fundamental basics and learn how to compare string or char and what is difference between "==" and equals() method. — Ranjeet, Apr 24 '15 at 05:36
Thanks guys, yeah it works when I replace 'input == "y"' with '(input.trim()).equals("y"))' Wow it's amazing how the smallest errors can make me sit for hours on end trying to find a solution. StackOverflow you are my hero — Jasper Squire, Apr 24 '15 at 05:36
@Ranjeet In my classes, we haven't learnt the equals() method, we're still using "==" so that's why I relied on it. I've learnt from my mistake though, thank you. — Jasper Squire, Apr 24 '15 at 05:38

score 0 · Accepted Answer · answered Apr 24 '15 at 05:20

0

Compare String by equals not by ==

if((input.trim()).equals("y")){

equals compares the value
== comapres the reference

answered Apr 24 '15 at 05:20

singhakash

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score 0 · Answer 2 · answered Apr 24 '15 at 05:20

Compare with equals.

if(input.equals("y")){
            System.out.println("Great! Let's get started.");
            break;
        }
        else if(input.equals("n")){
            System.out.println("Come back next time, " + name + ".");
            System.exit(0);
        }

Java: if/else statement in infinite loop not working

2 Answers2