CODEWITHSUNDEEP
java
etritb
etritb

Reputation: 73

Cannot call method in main method

I'm trying to call a method in another method (like in C#), like this:

public class Exercise1
{
   Scanner scanner = new Scanner(System.in);
   public int FirstNumber;
   public int SecondNumber;
   public int Answer;

   public static void main(String [] args)
   {
       GetNumbers();
   }

   private void GetNumbers()
   {
       System.out.print("Type in the first number: ");
       FirstNumber = scanner.nextInt();

       System.out.print("Type in the second number: ");
       SecondNumber = scanner.nextInt();

       Answer = FirstNumber + SecondNumber;

       System.out.print("The answer is: " + Answer);
   }
}

Why can't I call the method like that?

Upvotes: 2

Views: 7994

Answers (3)

SpringLearner
SpringLearner

Reputation: 13854

main is static method whereas GetNumbers() is not static either make GetNumbers() to static or create an object in main then call GetNumbers()

like this way

public class Exercise1
{
   Scanner scanner = new Scanner(System.in);
   public int FirstNumber;
   public int SecondNumber;
   public int Answer;

   public static void main(String [] args)

   {
Exercise1 e=new Exercise1();
       e.GetNumbers();
   }

   private void GetNumbers()
   {
       System.out.print("Type in the first number: ");
       FirstNumber = scanner.nextInt();

       System.out.print("Type in the second number: ");
       SecondNumber = scanner.nextInt();

       Answer = FirstNumber + SecondNumber;

       System.out.print("The answer is: " + Answer);
   }
}

or

    public class Exercise1
{
   static Scanner scanner = new Scanner(System.in);
   public static int FirstNumber;
   public static int SecondNumber;
   public static  int Answer;

   public static void main(String [] args)

   {
GetNumbers();
   }

   private static void GetNumbers()
   {
       System.out.print("Type in the first number: ");
       FirstNumber = scanner.nextInt();

       System.out.print("Type in the second number: ");
       SecondNumber = scanner.nextInt();

       Answer = FirstNumber + SecondNumber;

       System.out.print("The answer is: " + Answer);
   }
}

Upvotes: 2

Suresh Atta
Suresh Atta

Reputation: 122026

You cannot access non static methods in a static context.

Since main method is static you cannot access non static methods inside it.

Possible solutions:

Solution 1.

Make your GetNumbers(); as static. Then you are able to access it.

  private static void GetNumbers()
   {
      }

But, I won't recommend in your case, because you are accessing other instnace mebers too in GetNumbers() method. So they also needs to be static.

Solution 2.

Create new object for Exercise1 class inside main method.

  public static void main(String [] args)
   {
       Exercise1 ex= new Exercise1();
       ex.GetNumbers();
   }

   private  void GetNumbers()
   {
       System.out.print("Type in the first number: ");
       FirstNumber = scanner.nextInt();

       System.out.print("Type in the second number: ");
       SecondNumber = scanner.nextInt();

       Answer = FirstNumber + SecondNumber;

       System.out.print("The answer is: " + Answer);
   }

And as a side note:

Please follow java naming conventions, variable names stats with small letter's.

   public int firstNumber;
   public int secondNumber;
   public int answer;

Upvotes: 9

Sage
Sage

Reputation: 15428

GetNumbers(); needs to be static. A static method can only call a static method or use static fields.

However, but it can access object.GetNumber() if the object instance of Exercise1 is local to the main(). That is, create an instance object of Exercise1 in main() method to access that Exercise1 object's GetNumber() method.

Upvotes: 4

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