吸气剂和吸气剂

Question

So, I have written a code that is supposed to take two ints -f and s (first and second) - and return the sum. Eclipse didn't really like what I was doing, so I changed my code and added some getters and setters - which I am very unfamiliar with. I got Eclipse to create my getters and setters. My code still doesn't work, but I don't really know why.

Here it is:

public class Main extends Comp{

    public static void main(String[] args){
        Comp.give(getF(), getS());
    }
}




import java.util.Scanner;
//Feel the rhythm
//Feel the rhyme
//Come on Eclipse
//It's coding time!!!
public class Comp {
    private int f;
    private int s;
public void look(){
    Scanner iscan = new Scanner(System.in);
        setF(iscan.nextInt());
        setS(iscan.nextInt());
        iscan.close();  

}
public static void give(int f, int s) {
    System.out.println(f+s);

    }
public int getS() {
    return s;
}
public void setS(int s) {
    this.s = s;
}
public int getF() {
    return f;
}
public void setF(int f) {
    this.f = f;
}


}

The Problem - Eclipse has underlined getF(), getS() (Main method only) in red. When I hover over it, it says change getF() to static [same for getS()], but I don't want it to be static.

It also used this.f and this.f. I kinda know what that means, but not too well. An explanation of that would be great.

Answer 1

this.f refers to the instance variable f in your Comp class. Since the parameter for setF(int f) is also called f , the this helps distinguish between the two. It's basically saying "assign the method parameter f to my instance variable f ".

As for the error, you'd either need to make getF() and getS() static, or create an instance of your Comp class in main and call the two methods using that:

public static void main(String[] args){
    Comp comp = new Comp();
    Comp.give(comp.getF(), comp.getS());
}