CODEWITHSUNDEEP
java
borra
borra

Reputation: 13

how to reffer non static variable from static method?

Q)i got one compile error 10::non-static variable this can not be refferenced from the static content

what to do now??

class Computer
{    
  void method()    
  {    
     System.out.println("this i objects");
  }


   public static void main(String[] args)    
    {    
      Laptop mtd = new Laptop();
      Computer mtd1 = new Computer();
      mtd.method();
      mtd1.method();
     }  


class Laptop
  {    
    void method()    
     {    
      System.out.println("using laptop method");         
     }    
  }    
}

Upvotes: 0

Views: 70

Answers (2)

Stephan Henningsen
Stephan Henningsen

Reputation: 3783

Laptop is an inner class of Computer, thus you have to instantiate Laptop from a Computer instance. Or you can mark your inner Laptop class as static, then you can instantiate it directly. My example demonstrates both approaches:

class Computer
{

  public static void main(String[] args)
  {
      Computer computer = new Computer();
      computer.method();

      // Instantiate normal inner class from instance object.
      Laptop laptop = computer.new Laptop(); // Or: new Computer().new Laptop();
      laptop.method();

      // Instantiate static inner class directly.
      StaticLaptop staticLaptop = new StaticLaptop();
      staticLaptop.method();
  }

  void method()    
  {
      System.out.println("I'm Computer!");
  }


  class Laptop
  {
      void method()
      {
        System.out.println("I'm Laptop!");  
      }
  }

  static class StaticLaptop
  {
      void method()
      {
        System.out.println("I'm StaticLaptop!");  
      }
  }

}

Upvotes: 1

P45 Imminent
P45 Imminent

Reputation: 8591

You've put Laptop inside the Computer class.

You should refactor to static class Laptop. Otherwise you are tying a Laptop instance to a specific Computer instance, which you probably don't want to do. (If you really wanted to do that, you'd have to write new Computer().new Laptop();)

Although I think, in reality, you want to write

class Laptop extends Computer

which is called inheritance.

Upvotes: 0

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