CODEWITHSUNDEEP
javatypes
Dexter1403
Dexter1403

Reputation: 35

Changing the data type in java

The title seems common, but I can't find answers on other related questions. Our prof tasked to complete the source code he provided us. We are working on a phonebook. This phonebook have two separate classes namely Contact and PhoneBook. Here is the incomplete code for the PhoneBook.

public class PhoneBook {

  Contact contact[] = new Contact[10];
  int size = 10, capacity = 0;

  public PhoneBook(int capacity) {
    capacity++;
  }

  public boolean add(Contact newContact) {
    if (capacity < 11) {
      contact[capacity] = newContact;
      return true;
    } else {
      return false;
    }
  }

  public boolean delete(Contact contact) {
    //fill-in code
    return false;
  }

  public boolean update(Contact oldContact, Contact updatedContact) {
    boolean found = false;
    for (int i = 0; i < capacity; i++) {
      // fill-in code
    }
    return found;
  }

  public Contact search(String name) {
    for (int i = 0; i < capacity; i++) {
      // fill-in code
      // you may use the string.toLowerCase() and
      // string.equals(anotherstring) methods to check
      // the equality of two strings
    }
    return null;
  }

  public int getSize() {
    return this.size;
  }

  public Contact[] getContacts() {
    return this.contacts;
  }

  public int getCapacity() {
    return this.capacity;
  }
}

My problem is the method public Contact search(String name). We were told to check the equality of the strings in order to match the search of names in a phonebook, also to execute the delete method, updateContact and such. But, the variable name is a String type and the variable contact is a Contact type array. This is the contact class.

public class Contact {

  String name;
  String contactNumber;

  public Contact(String name, String contactNumber) {
    this.name = name;
    this.contactNumber = contactNumber;
  }

  public String toString() {
    return "Name: " + name + ", Contact No: " + contactNumber;
  }

  public String getName() {
    return this.name;
  }

  public String getNumber() {
    return this.contactNumber;
  }
}

If I included the whole phonebook source code here it will be too long. I just need to compare name and contact but I can't because they are of different types. What shall I do?

Upvotes: 1

Views: 397

Answers (2)

itfedorovsa
itfedorovsa

Reputation: 141

contact[i].name is a String type. I guess you should to try this:

public Contact search(String name){
        for(int i = 0; i < capacity; i++){
        if (contact[i].name.equals(name)) {
        ...your code...
        }

Don't forget ".toLowerCase()".

Upvotes: 1

muhrahim95
muhrahim95

Reputation: 119

Every time you create a contact, you will have something like this to instantiate a new contact object:

Contact contact = new Contact("Alice", contactNumber);

Also, in your class, you have a getName() method defined. If you assign a otherName variable, as follows, it will return the value "Alice" for you.

String otherName = contact.getName();

You can verify this by either debugging or by adding a print statement.

So to verify equality in these two objects, you can just run name.equals(otherName) which returns true or false.

However, since this is case-sensitive, you can instead use one of the following approaches:

  • name.equalsIgnoreCase(otherName)
  • name.toLowerCase().equals(otherName.toLowerCase())

In my opinion, the first is cleaner, but based on the comments you may have to use the latter, which I find less readable.

Another approach here would be: Objects.equals(name.toLowerCase(), otherName.toLowerCase()).

Upvotes: 2

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