I have a simple code in java that always returns "Game over.".
import java.util.Scanner;
public class nextQuestion {
    public void newQuestion() {
        Scanner choice2 = new Scanner(System.in);
        System.out.println("What is my name?");
        System.out.println("A. Mark");
        System.out.println("B. Robert");
        System.out.println("C. Mio");
        System.out.println("D. Samantha");
        String answer2 = choice2.nextLine();
        if(answer2 == "a" || answer2 == "A") {
            System.out.println("Game over.");
            System.exit(0);
        } else if(answer2 == "b" || answer2 == "B") {
            System.out.println("Nice guess!");
            System.exit(0);
        } else if(answer2 == "c" || answer2 == "C") {
            System.out.println("Game over.");
            System.exit(0);
        } else if(answer2 == "d" || answer2 == "D") {
            System.out.println("Game over.");
            System.exit(0);
        } else {
            System.out.println("Game over.");
            System.exit(0);
        }
    }
}
However if I use switch statement, it does work. What is the problem with this?
 
     
    