Question

in Java, I am writing a program where you need to pick a color. The color must be red, blue, or green and is a user input. If they put in a different value I need the program to stop running. So I essentially need to write code that says, if variableColor does not equal "red", "blue", or "green" then I need to print the statement "invalid response" and exit the program. How can I write this?

Answer 1

import java.util.Scanner;

public class ColorChooser {  

public static void main(String[] args)
   {
       String color;
       Scanner scan = new Scanner(System.in);
       // input the color
       System.out.print("Enter a color: ");
       color = scan.nextLine();
      
       // validate color is in ["red", "blue" , "green"] in any case, if not display invalid response
       if(!color.equalsIgnoreCase("red") && !color.equalsIgnoreCase("blue") && !color.equalsIgnoreCase("green"))
           System.out.println("Invalid response");
       else
       {
           // perform the steps required
           System.out.println("Valid response");
       }
   }
}

//end of program

Output: