Transmit Int

[Jey]

Hi. My problem is smiling. Ive got 2 file *.class

1st file

import java.io.IOException;
public class Vyber {
  
    public static int x;
    
    public static void vyber() throws IOException {
        volba.vyberSi(x);
        System.out.println(x+" vyber");
        switch(x){
            case 1: radkove_orientovany_IO.zapisDoSouboru();
            case 2: bajtProud.bP();
            case 3: znakProud.zP();
            case 4: scanner.sc();
            case 5: desCarka.dC();
        }
        
    }
}

2nd file

import java.util.*;

public class volba {    
    public static int vyberSi(int x){
       Scanner sc = new Scanner(System.in);
       x = sc.nextInt();
       System.out.println(x+ " volba");
       return x;
    }
}

I dont know how transmit int x. In class volba is x allright, but in class Vyber int x isnt the same number.

Thanks for any response.

[Norm]

The caller of the vyberSi method will receive from that method the value of x. It needs to store what is returned by that method into a local variable. Your code does not store the returned value.

[Jey]

Can I ask for writing code, please? I dont know where I have mistake.

[Norm]

Where is the value of x that you want to be "transmitted"?
From your code. Here is a sample of how you save the value returned by the nextInt() method in x:
x = sc.nextInt();

do the same for your method.

[Jey]

Ooops ... Thanks for reaction. Now I know wheres problem but I dont know how write that :-X.

[Norm]

but I dont know how write that

Please explain what you are trying to do?
Where is the value of x that you want to be "transmitted"?

[Jey]

I want enter number (x) from class volba to class Vyber, where is Switch (Vyber). I want make a little menu. I can do it in one class, but I want to work with parameter passing.
PS: Sorry for my (little) bad english

[Norm]

number (x) from class volba to class Vyber

What does your vyberSi method do? Does it return the value of x that you want?

You Call that method from the Vyber class to get the value of x.
What does this line do? It calls the vyberSi method but does NOT save the returned value.

volba.vyberSi(x);

[JeffGrigg]

I think that the point of confusion is...

• Java does "pass by value."

This means that volba can't change the value of the caller's variable 'x'. The 'x' in volba has nothing to do with the 'x' in Vyber. The two are not connected. Changing one does not change the other.

So Vyber needs to do this:

        x = volba.vyberSi(x);

Once that works, some of the other things the code does (which do not help) could be cleaned out.

[Jey]

Ou yes! Thank you very much ... WORKS! :-)