Question

I’m facing some problems with java classes.

Here is a class I defined

public class Condutor {
    private String name;

    public Condutor() {
        name = ""; 
    }

    public Condutor(String aName) {
        this.name = aName;
    }

    public void setName(String aName) {
        name = aName;
    }

    public String getName() {
        return name;
    }

    @Override
    public String toString() {
        return name;
    }

}

and on the main I have this

public static void main(String[] args) {
    Condutor[] names = new Condutor[10];
    Condutor name = new Condutor();
    String aName = "";

    for (int i = 0; i < 2; i++) {
        aName = "Mike" + i;

        name = new Condutor(aName);
        names[i] = name;      
    }

    for (int i = 0; i < 10;i++) {
        System.out.println(names[i]);
    }

} 

This works as expected printing this:
Mike0
Mike1
null
null
null
null
null
null
null
null

Maintaining the same class but changing

name = new Condutor(aName);
names[i] = name;

by

name.setName(aName);
names[i] = name;
System.out.println("------");
System.out.println(names[i]);
System.out.println("------");   

it prints

------
Mike0
------
------
Mike1
------
Mike1
Mike1
null
null
null
null
null
null
null
null

I can see that in the loop everything works as expected but the names array stores in the first two positions the last input.

Why does this happens?
Should’t it store exactly as in the loop?

regards,

Favolas

Answer 1

You need to create new objects in the second case too:

name = new Condutor(); //add this line to make sure you create new object in every iteration
name.setName(aName);
names[i] = name;
System.out.println("------");
System.out.println(names[i]);
System.out.println("------");