Question

I was being questioned by this, why can’t I declare all methods static? Can you give me a piece of explanation in here? Thanks.

I believe that when you make a method static, it cannot access non-static members?

Answer 1

Static methods cannot access instance variables. 🙂

public class MyStaticExample{
  private String instanceVariable = "Hello";
  private static String STATIC_VARIABLE = "Hello too";

  public static void staticMethod(){
    System.out.println(this.instanceVariable); // this will result in a compilation error.
    System.out.println(STATIC_VARIABLE); // this is ok
  }

  public void instanceMethod(){
    System.out.println(this.instanceVariable); // this is ok
    System.out.println(STATIC_VARIABLE); // this is ok
  }
}