Question

I’m trying the static and non-static methods and fields.
I tried to compile this:

class main{
    public int a=10;
    static int b=0;
    public static void main(String[] args){
        b+=1; //here i can do anything with static fields.
    }
}

class bla {
    void nn(){
        main.a+=1; //why here not? the method is non-static and the field "main.a" too. Why?
    }
}

and the compiler returns me:

try.java:10: non-static variable a cannot be referenced from a static context

but why? The method and the field “a” are both non-static!

Answer 1

You are attempting to access a in a static manner. You will first need to instantiate main to access a.

main m = new main();
m.a += 1;

Also, for readability, you should capitalize the names of Classes, and camel case your instance variables.