How to Sort an Array of Objects by Name in Java?

Sorting Arrays of Objects in Java

Problem:

You have an array of objects that do not contain strings but instead have object references. Each object reference provides information about name, ID, author, and publisher through a toString method. The task is to sort this array by the name field. However, you are uncertain how to extract the name from each object and use it as the sorting criteria.

Solution:

To extract the name from each object and sort by this field, you can use the following approach:

List<Book> books = new ArrayList<Book>();

Collections.sort(books, new Comparator<Book>() {
  @Override
  public int compare(Book o1, Book o2) {
    return o1.getName().compareTo(o2.getName());
  }
});

In this example:

• List is a list representing your array of objects.
• Collections.sort is used to sort the list.
• new Comparator() {...} defines a custom comparator to determine the sorting order.
• o1.getName() extracts the name field from the first object using the getter method or direct access if the field is public.
• o2.getName() extracts the name field from the second object.
• compareTo compares the extracted names, returning a negative value if the first name is smaller, a positive value if it's larger, and zero if they are equal.

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