How to add an object to an ArrayList in Java

Question

I want to add an object to an ArrayList, but each time I add a new object to an ArrayList with 3 attributes: objt(name, address, contact)

Answer 1

Try this one:

Data objt = new Data(name, address, contact);
Contacts.add(objt);

Answer 2

change Date to Object which is between parenthesis

Answer 3

Contacts.add(objt.Data(name, address, contact));

This is not a perfect way to call a constructor. The constructor is called at the time of object creation automatically. If there is no constructor java class creates its own constructor.

The correct way is:

// object creation. 
Data object1 = new Data(name, address, contact);      

// adding Data object to ArrayList object Contacts.
Contacts.add(object1);                              

Answer 4

You need to use the new operator when creating the object

Contacts.add(new Data(name, address, contact)); // Creating a new object and adding it to list - single step

or else

Data objt = new Data(name, address, contact); // Creating a new object
Contacts.add(objt); // Adding it to the list

and your constructor shouldn't contain void. Else it becomes a method in your class.

public Data(String n, String a, String c) { // Constructor has the same name as the class and no return type as such

Answer 5

You have to use new operator here to instantiate. For example:

Contacts.add(new Data(name, address, contact));