Java Question about Setting a Word as a Variable

Question

I am making a rock paper scissors program. I want the user of the program to enter either rock, paper, or scissors (hence the imported scanner) and I want the computer to choose a random number (I will import a java.util.Random) that corresponds to another rock, paper, or scissor.

So I am trying to make the program RECOGNIZE a word as something significant. That is to say, if the user inputs "rock" in the scanner, the computer will do some output. In the below code, I tried to get the computer to output "yes" if the user inputs "rock". To do this, I set a variable called "player" to be the inputted text, and a String rock to be the phrase "rock". I then said that if player=rock(="rock"), then we will get "yes".

There were no errors in the program. But when I inputted "rock" into the scanner, the program did nothing. What did I do wrong and how can I correct it?

import java.util.Scanner;

public class Refined {

    public static void main(String[] args){
        Scanner abc = new Scanner(System.in);
        String rock = "rock";

        String player;
        System.out.println("Rock, Paper, or Scissors?");
        player = abc.next();
        if(player == rock){
            System.out.println("yes");

        }
    }

There are soo many duplicates... search for "java string equals" — , Jun 28 '12 at 05:59

score 1 · Answer 1 · answered Jun 28 '12 at 05:00

Use player.equals(rock) or player.equalsIgnoreCase(rock) to compare contents of both variables

If we apply == to compare two string objects it compares the references of both the objects so in your case references are difference that is why it is returning false and System.out.println("yes"); is not being printed.

Use String.equals() or String.equalsIgnoreCase() method to compare contents of the string.

score 0 · Answer 2 · answered Jun 28 '12 at 03:41

0

You want player.equals(rock) in the if condition.

Putting player == rock compares the String objects (basically whether the references in memory point at the same spot), not the value actually stored in the String objects.

answered Jun 28 '12 at 03:41

Luke Mathieson

101
3

score 0 · Answer 3 · answered Jun 28 '12 at 05:57

0

player and rock are String objects. In Java we dont have String as a datatype, like int, float, etc. So to compare two objects we must use .equals() [ which comes from the Object class ]

answered Jun 28 '12 at 05:57

codingsplash

4,785
12
51
90

Java Question about Setting a Word as a Variable

3 Answers3