从内部类内部访问局部变量user_input； 需要宣布为最终

Question

import java.util.Scanner;

public class Testing {

    public static void main(String [] args)  {

        Scanner user_input = new Scanner( System.in );

        String start;
        System.out.print("(Don't put capital letters) ");

        String color;
        System.out.print("Enter Your Favorite Color: ");
        color = user_input.next ( );

        String animal;
        System.out.print("Enter Your Favorite Animal: ");
        animal = user_input.next ( );

        String preference;
        preference = color + " and that your favorite animal is a " + animal;

        System.out.println("From the information I gathered, I figured out that you like the color " + preference);

        class A {
            public void Main(String[] args) {
                Scanner input = new Scanner(System.in);
                    System.out.println("Do you want to hear a joke?");
                String a = user_input.next ( );

                if (a.equalsIgnoreCase("yes")) ;
                    System.out.println("What did the fish say when he ran into a wall? Dam");

                if(a.equalsIgnoreCase("no")) ;
                    System.out.println("Oh..."); }

        }
    }
}

and this is the error

Testing.java:29: error: local variable user_input is accessed from within inner class; needs to be declared final
    String a = user_input.next ( );
               ^

1 error

I've just been messing around with the code and the errors go up and up so i decided to ask someone more experienced than myself. I have been using java for only a day and this is my first program that i've created, i've searched for at least 2 hours for a solution but couldn't find one, so i decided to ask. I got it to compile before, but it was without "user_input.next" so it acted like the whole line of code below "class A" was invisible and it wouldn't let me type anything, making it useless. I than put in user_input so that i could input something, but TONS of errors came up, but this is the one error that keeps popping up.

Answer 1

The error is most likely caused by you declaring a scanner ( input ) and then using the scanner from the other class ( user_input )

Try this code

import java.util.Scanner;

public class Testing 
{
    public void input1()
    {
        Scanner user_input = new Scanner( System.in );

        System.out.print("(Don't put capital letters) ");

        String color;
        System.out.print("Enter Your Favorite Color: ");
        color = user_input.next();

        String animal;
        System.out.print("Enter Your Favorite Animal: ");
        animal = user_input.next();

        String preference;
        preference = color + " and that your favorite animal is a " + animal;

        System.out.println("From the information I gathered, I figured out that you like the color " + preference);
    }

    public void input2()
    {
        Scanner input = new Scanner(System.in);
        System.out.println("Do you want to hear a joke?");
        String a = input.next();

        if(a.equalsIgnoreCase("yes"))
        {
            System.out.println("What did the fish say when he ran into a wall? Dam");
        }
        else if(a.equalsIgnoreCase("no"))
        {
            System.out.println("Oh...");
        }
    }

    public static void main(String[] args)
    {
        Testing tS = new Testing();
        tS.input1();
        tS.input2();
    }
}

In this code there are two methods; input1 and input2 . These methods contain the two conversations you tried to have with your command console. Then in the main method the class is initialized and it runs the two methods.

Answer 2

I hope you want to do this

public class Test2 {
private static Scanner user_input = new Scanner(System.in);

private static boolean wantsToContinue(){
    System.out.println("Do you want to hear a joke?");
    String a = user_input.next();
    if(a.equalsIgnoreCase("yes"))
        return true;
    else
        return false;
}

public static void main(String[] args)
{    
    System.out.print("(Don't put capital letters) ");

    System.out.print("Enter Your Favorite Color: ");
    String color = user_input.next();

    System.out.print("Enter Your Favorite Animal: ");
    String animal = user_input.next();

    String preference = color + " and that your favorite animal is a " + animal;
    System.out.println("From the information I gathered, I figured out that you like the color " + preference);


    if(!wantsToContinue()){
        //If not want to continue just return
        System.out.println("Oh...");
        return;
    }

    //Continue with your next joke here
    System.out.println("What did the fish say when he ran into a wall? Dam");

}

}