Objects in an Array (of an Object) - java help on CodeGym

hey, friends : ) after learning the basics of Objects, I wanted to try to make an own practice project, which should be simple but somehow I dont have the expected outcome what I got is: class team with this variable and function to create new agents

public static agent[] members = new agent[3];

    public static void setAgents() throws IOException {
        System.out.println("You can create up to 3 Agents for " + name);
        for (int i = 0; i < members.length; i++){
            members[i] = new agent();
            members[i].setName();
            System.out.println("Name: " + (members[i].getName())); //this returns the correct name of the created agent
        }
    }

Which should create 1 agent object for each array-member class agent looks like this (variables and function to set/get the name

public class agent {
    public static String name;
    public static int HP;
    public static int ATK;
    public static int DEF;
    public static boolean isAlive = true;

    public void setName() throws IOException {
        System.out.println("Hi, please type in the name for your agents:");
        BufferedReader reader = new BufferedReader(new InputStreamReader(System.in));
        name = reader.readLine();
    }

    public static String getName() throws IOException {
        return name;
    }

but when I try to show all the agents of the team afterwards, only the name of the last added agent is shown

public static void showTeam () throws IOException {
       System.out.println("This is your current team");
       for (int i = 0; i < members.length; i++){
           System.out.println("Agent 0" + i);
           System.out.println("--------------------");
       }
   }

can someone please help me, seems like I didnt understand the Basics of Objects fully : ( thanks in advance : )

public class Solution { public static void main(String[] args) { Student[] students = new Student[5]; for(int i = 0; i < students.length; i++) { students[i] = new Student(); System.out.println("Student created. Value of static variable: " + Student.count); } System.out.println("\nOutputting all students"); for(Student x : students) System.out.println(" " + x); System.out.println("\nOutputting value of static variable on all students:"); for(Student x : students) System.out.println(" " + x.count); } } class Student { static int count; int ID; public Student() { ID = count; count++; } public String toString() { return "Student ID = " + ID; } }

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Cec

Level 13

17 June 2022, 14:00

I removed the statics in the variables etc., and it worked smoothly, thanks again, mate @Guadalupe Gagnon!

Guadalupe Gagnon

Level 37 , Tampa, United States

17 June 2022, 14:13

😁 I just wanted to say that its awesome that you are making up your own practice tasks. I think that, if you stick with it, you are going to make a really good programmer.

17 June 2022, 14:19

thanks, mate :D they are not really complex or anything though, but I m trying to stick to it :)

17 June 2022, 13:57

ah thanks for a detailed explanation @Guadalupe Gagnon, it really helped a lot to clarify things for me , I knew I was missing something I tried to run your code after guessing the outcome, I wasnt fully correct, but I think I understood it now I will try to fix my code :)

17 June 2022, 13:30

solution

This is due to your class fields being static:

public static String name;
public static int HP;
public static int ATK;
public static int DEF;
public static boolean isAlive = true;

The static modified marks a field or method as part of the class and not specific to an object of that class. When a class is first loaded into memory each static field is given a block of memory. This block of memory can be accessed by any object of that class, or by just using the class name. When objects of a class are created blocks of memory are given for each non-static field. Blocks of memory are where values are stored, which would be retrieved when needed. So lets say you had a Student class with a static int field and a non-static int field. When the class is first loaded into memory (this occurs prior to it being used) then a block of memory would be given to the static int field. For each object you create of this Student class a block of memory is given for the non-static int field. So if you created 5 Student objects then there would be: - 1 block of memory for the static field - 1 block of memory for each of the 5 objects In your code you have created 3 objects, but there are only 5 blocks of memory (1 for each static field. Instead you would want 15 blocks of memory (5 blocks for each object created).

17 June 2022, 13:36

Here is a quick example:

Try to predict the output, then run it and see if you were correct.