Search ArrayList object : object's

Question

I struggled to find a solution or at least to point me in the right direction...

Here is my ArrayList: books = new ArrayList();

I have to search objects of Book that contain a title(String). Here is what I have..

The problem being is that I only want to print the second statement if it is not found. But it seems to be printing it as it searches each object in the list?

public void searchBookInCollection(String title) 
{
    for (Book book : books)
    {
        if(book.getTitle().equalsIgnoreCase(title)) 
        {
            book.displayBookInformation();
        }
        else
        {
            System.out.println("Nope we don't have it");
        }
    }
 }

Michael Markidis · Accepted Answer · 2017-06-21 04:29:05Z

2

change it to have a boolean found flag

public void searchBookInCollection(String title) 
{
      boolean found = false;
      for (Book book : books)
      {
            if(book.getTitle().equalsIgnoreCase(title)) 
            {
               book.displayBookInformation();
               found = true;
               break;  // no point to keep going? 
            }
       }
       if (!found)
       {
           System.out.println("Nope we don't have it");
       }
}

edited Jun 21, 2017 at 4:29

Michael Markidis

4,1911 gold badge16 silver badges21 bronze badges

answered Jun 21, 2017 at 4:19

Scary Wombat

44.9k6 gold badges38 silver badges67 bronze badges

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

3 Comments

Blackbox10101 Over a year ago

Thank you very much. I guess I didn't consider looking outside of the for each for the second statement. My teacher has mentioned about not using breaks(outside of case statements) because we should allow the loop to break itself in most situations? Do you understand what they mean?

Scary Wombat Over a year ago

Do you understand what they mean? if you are looping using a while loop or standard for you can just set the terminating condition, cause it to break e.g. while (!found) But as you are using a for-each type of for then how I coded is good.

Michael Markidis Over a year ago

@ScaryWombat No problem. Any time.

patrik · Accepted Answer · 2017-06-21 04:59:47Z

0

Since the method says searchBookInCollection() it is expected to return a book or a name or something. This gives an alternative solution,

public String findBook(String title) { // "InCollection" does not help end user, "find" follows standard naming convention
    for (String book : books) {
        if (book.equalsIgnoreCase(title)) {
            return book; // This is debated, if you want "one return" here, use temporary variable.
        }
    }
    throw new NoSuchElementException("Title was not found!"); // Throw gives the end user a chance to handle the exception.
}

answered Jun 21, 2017 at 4:59

patrik

4,5586 gold badges31 silver badges55 bronze badges

Collectives™ on Stack Overflow

Search ArrayList object : object's

2 Answers 2

3 Comments

Comments

Your Answer

Hot Network Questions

Collectives™ on Stack Overflow

2 Answers 2

3 Comments

Comments

Your Answer

Sign up or log in

Post as a guest

Related