Get values from arraylist java?

Question

I have the following class

   public class Patient implements Serializable {

  private int id;

  private String name;

  private String desc;
    public Patient(int id, String name, String desc) {

    this.id = id;
    this.name = name;
    this.desc=desc;
    }

And then the following getter and setter methods in this class.

Declaring the arraylist

  ArrayList<Patient> list = new ArrayList<Patient>();

Adding run time data in the list

   list.add(new Patient(id++, name.getText(), disDesc.getText())

Now i want the read the elements stored in the list How can i do that?

    System.out.println(list.get(0));

I use this but it returns the object address of the class

Most IDE's such as Eclipse and IntelliJ will be able to automatically generate a toString override for your class. I'd use those, at least as a template. — Sebastiaan van den Broek
– Sebastiaan van den Broek, Commented Oct 5, 2013 at 11:39

Georgian · Accepted Answer · 2013-10-05 11:34:38Z

6

You have to override the toString() method of Patient. There, you will return all information on the Patient object that you want to display.

Example: (my personal favorite)

 private static final String SEPARATOR = ", ";

 @Override
 public String toString()
 {
      StringBuilder builder = new StringBuilder();

      builder.append("ID: ").append(id).append(SEPARATOR);
      builder.append("Name: ").append(name).append(SEPARATOR);
      builder.append("Desc: ").append(desc);

      return builder.toString();
 }

Example 2:

 @Override
 public String toString()
 {
      return "ID: " + id + ", Name: " + name + ", Desc: " + desc;
 }

Example 3:

 @Override
 public String toString()
 {
      return MessageFormat.format("ID: {0}, Name: {1}, Desc: {2}", id, name, desc);
 }

Use either one. It is a matter of preference.

edited Oct 5, 2013 at 11:34

answered Oct 5, 2013 at 11:27

Georgian

8,9908 gold badges50 silver badges92 bronze badges

Sign up to request clarification or add additional context in comments.

5 Comments

Jon Skeet Over a year ago

Why not just use: return "ID: " + id + " | Name: " + name + " | Desc: " + desc;? Simpler to read IMO, and just as efficient. Alternatively, use String.format.

Georgian Over a year ago

@JonSkeet From my knowledge, StringBuilder is more efficient than concatenating strings. Am I wrong? I've developed a habit for using StringBuilder.

WISHY Over a year ago

loved your personal favorite

Richard Tingle Over a year ago

I believe is everything is on a single command then java is clever and uses string buolder behind the scenes anyway

Georgian Over a year ago

@RichardTingle That's actually a really good idea for a SO question.

Aniket Kulkarni · Accepted Answer · 2013-10-31 10:32:54Z

2

You have to cast the element,

((Patient) list.get(0)).getName();

And you must add a public getter method to your Patient class.

edited Oct 31, 2013 at 10:32

Aniket Kulkarni

13k10 gold badges70 silver badges94 bronze badges

answered Oct 5, 2013 at 11:31

huembert

492 silver badges5 bronze badges

Collectives™ on Stack Overflow

Get values from arraylist java?

2 Answers 2

5 Comments

Comments

Your Answer

Hot Network Questions

Collectives™ on Stack Overflow

2 Answers 2

5 Comments

Comments

Your Answer

Sign up or log in

Post as a guest

Related