Question

Hello everyone I am trying to Iterate trough an Array and fill each Array element with a random value. the only problem is that i get weird outputs like

[I@4b142196

the example for this I found on Array Example

but when using this in my code it won’t work. Here is what I got:

package h05GrootsteWaarde;
import javax.swing.*;
import java.util.*;

public class GetallenGenerator extends JPanel {
    public GetallenGenerator() {
    }
    int[] val = new int[21];
    Random generator = new Random();    
    public void setRandomValue() {
        for (int i = 0; i < val.length; i++) {
            val[i] = generator.nextInt(201) - 100;
        }    
    }   
    public int[] getRandomValue() {     
        return val;     
    }
}

and here is how I call the function

package h05GrootsteWaarde;
import javax.swing.*;
import java.awt.event.*;
public class Bediening extends JPanel implements ActionListener {
    GetallenGenerator generator;
    private JButton bereken;
    private JTextArea veld;

    public Bediening(GetallenGenerator generator) {     
        this.generator = generator;     
        bereken = new JButton("Bereken kleinste");
        bereken.addActionListener(this);
        add(bereken);       
        veld = new JTextArea(13, 40);
        veld.setEditable(false);
        veld.setWrapStyleWord(true);
        veld.setLineWrap(true);
        add(veld);      
        generator.setRandomValue();
    }   
    public void actionPerformed ( ActionEvent e ) {     
        String hoi = " " + generator.getRandomValue();
        veld.append(hoi);       
    }
}

Answer 1

You get a strange output because array’s toString method does not show the string containing individual members of the array; instead, it shows a strange string starting in [I@ for arrays of primitive type int.

You should prepare the string manually, or call Arrays.toString(myArray), like this:

int[] arr = generator.getRandomValue();
String arrStr = Arrays.toString(arr);
String hoi = arrStr.substring(1, arrStr.length()-1);