What does T extends Comparable Super t mean?
The meaning is T implements Comparable interface! Also it means all the elements in the List must implement Comparable interface, or it should be mutually comparable. All Wrapper classes, String, Date etc implements Comparable.
Can you extend comparable?
The Interface can only extend the Interface. The Java class can only extend a Java class. As Comparable is an interface in Java, we must create a custom interface that will extend the Comparable Interface. The custom class will implement the custom interface.
Does string extend comparable?
Comparable interface is a generic type. A String can be compared to other String. But not with objects of a different class. extends, when applied to type parameters, actually means “extends or implements.”
What is comparable [] in Java?
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.
Why do we implement comparable interface?
Comparable interface is mainly used to sort the arrays (or lists) of custom objects. Lists (and arrays) of objects that implement Comparable interface can be sorted automatically by Collections.
What does Super t mean in Java?
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 .
Can an interface implement comparable?
In general, if you mark an interface as Comparable to itself, any correct implementation may only use methods from this interface to perform the comparison. Otherwise this relation can’t be made anti-symmetric – a necessary condition to have a consistent ordering.
Does string extend comparable Java?
Comparable , but your custom interface, located in the same (default) package as Test . So the compiler is correct: java. lang. String does not implement that interface of yours.
Is comparable a functional interface?
Answer: Yes, comparable is a functional interface. It declares a single abstract method, compareTo ().
Is comparable an interface?
The Comparable interface defines the compareTo method used to compare objects. If a class implements the Comparable interface, objects created from that class can be sorted using Java’s sorting algorithms.
What methods are in the comparable interface?
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 difference between extends and super in Generics?
super is a lower bound, and extends is an upper bound.