What does T extends Comparable mean in Java?

Implementing the Extends Comparable Interface in Java This method compares the object with the specified object for the order. It returns a negative integer if the object is less than specified. It will return zero if the object and the specified object are equal.

What does comparable t mean?

The Comparable interface consists of just one method (and no constants): int compareTo( T obj ) Compare this object with obj , which is of type T. Return a negative integer, zero, or a positive integer, when this object is less than, equal, or greater than obj . In the above, T stands for the type of the objects.

What is difference between T and in Java generics?

6 Answers. Show activity on this post. Well there’s no difference between the first two – they’re just using different names for the type parameter ( E or T ). The third isn’t a valid declaration -? is used as a wildcard which is used when providing a type argument, e.g. List

What is the comparable interface in Java?

Java Comparable interface is used to order the objects of the user-defined class. This interface is found in java. lang package and contains only one method named compareTo(Object). It provides a single sorting sequence only, i.e., you can sort the elements on the basis of single data member only.

What is T in generics in Java?

Generic Class Here, T is the data type parameter. T , N , and E are some of the letters used for data type parameters according to Java conventions. In the above example, you can pass it a specific data type when creating a GenericClass object.

What does Super t mean?

super T denotes an unknown type that is a supertype of T (or T itself; remember that the supertype relation is reflexive). It is the dual of the bounded wildcards we’ve been using, where we use? extends T to denote an unknown type that is a subtype of T . public static T writeAll(Collection coll, Sink

What is Java comparable interface?

The Java Comparable interface, java. lang. Comparable , represents an object which can be compared to other objects. For instance, numbers can be compared, strings can be compared using alphabetical comparison etc. Several of the built-in classes in Java implements the Java Comparable interface.

What is implement comparable?

The fact that a class implements Comparable means that you can take two objects from that class and compare them.

What does implements comparable mean?

You can also implement the Java Comparable interface yourself, to make your own classes comparable. When a class implements the Java Comparable interface, this means that instances (objects) of that class can be compared to each other, as mentioned above.

Is legal in Java?

This is a good answer. But it’s interesting in bounded generic types, Java doesn’t differentiate between interface implementation and class inheritance – >is not legal. – flow2k

What does mean in Java?

==>guhanvj, >means that is having upper bound of Comparable objects. So can have types of Byte, Character, Double, Float, Long, Short, String, and Integer classes which all implements Comparable interface for natural ordering.

How to implement Comparable interface in Java?

The working of comparable in java is as follows: To implement this interface, you must implement this method: T – is the type of object with which this object is compared to. compareTo method returns 0 if the object specified and this object is equal. It returns a negative integer if this object is less than the object specified.

What is the use of comparator utility method in Java?

This utility method returns a Comparator that imposes the reverse of the natural ordering on a collection of objects. This enables a simple idiom for sorting (or maintaining) collections (or arrays) of objects that implement the Comparable interface in reverse-natural-order.