What is diff between comparable and comparator?
Comparator
| Comparable | Comparator |
|---|---|
| Natural Ordering | Custom Ordering |
| Type of Object | |
| Objects in comparison must be of the same type | Objects of different classes are considered |
| Affect on Class |
When would you use a comparator instead of implementing comparable?
To summarize, if sorting of objects needs to be based on natural order then use Comparable whereas if you sorting needs to be done on attributes of different objects, then use Comparator in Java.
What is the use of comparator and comparable in Java?
Comparable v/s Comparator in Java Comparable interface is used to sort the objects with natural ordering. Comparator in Java is used to sort attributes of different objects. Comparable interface compares “this” reference with the object specified. Comparator in Java compares two different class objects provided.
How does a comparable and comparator work internally?
In Java, Comparable and Comparator are used for sorting collection of objects. java. lang. Comparable is used to sort collection of same types(classes) like List, List, List, It means Comparable is like “I can compare myself with another object of same type”.
What is comparable What is Comparator and how are they different when might you want to use one over the other?
1) Comparable provides a single sorting sequence. In other words, we can sort the collection on the basis of a single element such as id, name, and price. The Comparator provides multiple sorting sequences. In other words, we can sort the collection on the basis of multiple elements such as id, name, and price etc.
What are the benefits of implementing the Comparable interface?
In order to be able to use the built-in sort method, we need to implement Comparable interface. The Comparable interface is a generic interface that can be replaced by a concrete type. It defines a method comparedTo(T t): int for comparing objects. This implementation makes two objects comparable.
What is use of comparable and Comparator and its methods?
What does it mean to implement comparable?
The fact that a class implements Comparable means that you can take two objects from that class and compare them.
How does comparable affects the original class?
Comparable affects the original class i.e. actual class is modified. Comparator doesn’t affect the original class i.e. actual class is not modified. Comparable provides compareTo() method to sort elements.
What is the difference between comparable and comparator in Java?
Comparable vs Comparator in Java. Java provides two interfaces to sort objects using data members of the class: A comparable object is capable of comparing itself with another object. The class itself must implements the java.lang.Comparable interface to compare its instances. Consider a Movie class that has members like, rating, name, year.
Can we use comparator as a nested static class in Java?
You can provide custom Comparator as nested static class, because a Comparator is closely associated with the object it compare. This is one of the genuine usage of nested static class in Java. It’s good to provide natural ordering of object via compareTo () method and provide additional compare () methods for custom sorting of object in Java.
How do I sort a list using comparator in Java?
Make an instance of the Comparator class. Call the overloaded sort () method, giving it both the list and the instance of the class that implements Comparator. Comparable is meant for objects with natural ordering which means the object itself must know how it is to be ordered.
How to override compareTo() method in Java?
When overriding compare () method, if you find an object, which overrides compareTo () then invoke that, for example for comparing String and Date we are invoking their compareTo () methods. In order to run this program, simply copy-paste the following two classes into two different Java source files.