[Pustik]

Hey guys,
I need help with set method at Arraylist. I have ArrayList of class and I need to change atribute of this class in whole list. I want to use normal loop but problem is with set method. In code is just seriously easied version of real thing what I am doing but principal is same. I have no idea how to help and google didn't help:( Thanks for your help

/*
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 * and open the template in the editor.
 */

package procvicovanizakladu;

import java.util.ArrayList;

/**
For fun nejake zakladni operace a operandy. Tak si to vyzkousime
 */
public class Main {

    /**
     * @param args the command line arguments
     */
    public static void main(String[] args) {

    ArrayList<Pokus> a = new ArrayList<Pokus>();
    a.add(new Pokus(5));
    a.add(new Pokus(10));
    a.add(new Pokus(15));
    a.add(new Pokus(20)); //Adding files

    a.set(index, null);)/>   ///////Index is for sure, but how to change attribute c in class Pokus to any diffrend number?
    
    for(int i = 0 < a.size() ; i++)
    {
          System.out.println(a.get(i).c);  
    }

    }
}


And class Pokus:

package procvicovanizakladu;

/**
 *
 * @author Puštík
 */
public class Pokus {

    int c;
    public Pokus (int B)/>
    {
        c = b;
    }

}

[macosxnerd101]

The set() method for ArrayList deals with the Object, not the attributes of the Object. If you want to change an Object attribute, you have to get() the Object at index, and modify the attribute from there. For example:

list.get(someIndex).c = newValue;

[Pustik]

Thank you a lot, helped to unstuck me:)
Love this site

[macosxnerd101]

Glad I could help!