Java with switch

Question

i'm not entirely sure what is wrong with this java. i kept getting incompatible type when i run the program. I am only a beginner in java program. Please give me a hand in detail. i have tried various method and searched for many links in google. but i was just unfortunate. Write a program that asks the user to enter “air”, “water”, or “steel”, and the distance that a sound wave will travel in the medium. The program should then display the amount of time it will take.

Prompts And Output . The program prompts for the medium with: "Enter one of the following: air, water, or steel: " and reads the medium. If the medium is not air, water or steel the program prints the message : "Sorry, you must enter air, water, or steel." an nothing else. Otherwise the program prompts for the distance with ("Enter the distance the sound wave will travel: " and reads it in and then prints "It will take x seconds." where x is the time calculated by your program .

and this is what I have so far.

class one{ 
    public static void main(String[] args){ 
        Scanner input = new Scanner(System.in);

        System.out.print("Enter one of the following: air, water, or steel: ");
        String text = input.nextLine();

        System.out.print("Enter the distance the sound wave will travel: ");

        double distance;
        double time;

        distance = input.nextDouble();

        switch (text){
            case "air":
                time = (distance/1100);
                System.out.println("It will take " + time + " sconds." );
                break;

            case "water":
                time = (distance/4900);
                System.out.println("It will take " + time + " seconds.");
                break;

            case "steel":
                time = (distance/16400);
                System.out.println("It will take " + time + " seconds.");
                break;


            default:
                System.out.println("Sorry, you must enter air, water, or steel.");
        }    
    }
}

What error message did you get exactly? If it indicates a line number, please show which line that is. — Thilo, Feb 15 '15 at 03:21
I just ran it, and it seems work as intended. Please supply the exact input, as well as a copy of the error message. — Patricia Shanahan, Feb 15 '15 at 03:23
Note that Java 7 was the first version where you can actually use strings in switch/case. Maybe you use the wrong compiler level? — eckes, Feb 15 '15 at 03:41

score 2 · Answer 1 · edited May 23 '17 at 11:43

2

What version of Java are you using? Cannot use switch on a String in versions < Java 7. See Why can't I switch on a String?

Also suggest you use something like Eclipse to code Java which will pick up these errors.

edited May 23 '17 at 11:43

Community

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answered Feb 15 '15 at 03:29

Astra Bear

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I just changed the compliance level in my Eclipse test project to 1.6, and got a very nice clear explanation of what was wrong with the switch. – Patricia Shanahan Feb 15 '15 at 03:45
This should have been posted as a comment, not as an answer. – reformed Feb 15 '15 at 21:50
@reformed I agree, but I didn't have enough points so I had to start somewhere. – Astra Bear Feb 15 '15 at 22:27

Dyrandz Famador · Answer 2 · 2015-02-15T03:56:51.287

so your compiler might be lower version.. switch in string will not work in Java 6 and before.

upgrade your JDK to higher version. Download latest JKD here

in the JDK 7 release, you can use a String object in the expression of a switch statement:

Instead of using alternative like if else,

It would be better to upgrade your JDK.

note: String objects in switch statements is case sensitive so before comparing the string, you can make the inputted string to uppercase 'coz the switch statement is case sensitive.

Java with switch

2 Answers2