CODEWITHSUNDEEP
java
Lazio
Lazio

Reputation: 105

What parameters should I use for the contains() method?

I don't really understand what parameters I should pass to the contains() method. I have my own class called Name which consists of 2 strings (firstName, secondName). I have created an ArrayList of type Name and 2 Name objects of the same name e.g. ("Joe, "Bloggs") 2x. So what paremeters do I have to pass to check whether it works. I have correctly overriden the equals method for Name class. This is my main program: 

import java.util.ArrayList;

public class EqualsTest {

    public static void main(String[] args) {

        ArrayList<Name> names = new ArrayList<Name>();

        names.add(new Name("Joe", "Bloggs"));
        names.add(new Name("John", "Smith")); //<--
        names.add(new Name("Alan", "Wake"));  //   | the same name
        names.add(new Name("Robert", "High"));//   |
        names.add(new Name("John", "Smith")); //---

        names.contains(Name("Joe", "Bloggs"));      
    }
}

Upvotes: 1

Views: 207

Answers (2)

Ruchira Gayan Ranaweera
Ruchira Gayan Ranaweera

Reputation: 35577

You can use 

names.contains(new Name("Joe", "Bloggs"));

But you should override equals() method in Name class to work it as expected.

When ever you need to deal with collection frame work in Java, better to override both equals() and hashCode() method in your classes else you end up with mess.

Upvotes: 2

Eran
Eran

Reputation: 393936

Assuming you've overridden equals correctly in your Name class, it should be:

 if (names.contains(new Name("Joe", "Bloggs"))) {
     ...
 }

Upvotes: 7

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