How to declare method signature for generic method in Java?

Generic method signature includes type variable declaration, parameter type and return type. The specified type variable precedes the method name, and the parameter and return types can be primitive or generic types. For example, <T, U> void myMethod(T arg1, U arg2) represents a method signature that accepts two parameters of different types. This method signature allows writing flexible code that can be used with a variety of types, such as the add() method in the java.util.LinkedList class, which uses a generic E to handle various element types.

#How to declare a method signature for a generic method in Java?

Java Generics allow you to write code that works with various types. The signature of a generic method specifies the type variables used with the method.

Syntax:

<typeVariable1, typeVariable2, ..., typeVariableN> returnType methodName(parameterType1, parameterType2, ..., parameterTypeN)

Type variable declaration:

Generic type variable declaration for method signature must precede the method name .

Example:

To declare a generic method that accepts two parameters, you can use the following signature:

<T, U> void myMethod(T arg1, U arg2)

This means that the method accepts two parameters parameters, which are instances of type T and type U respectively.

Parameter type:

The parameter type of a generic method can be a primitive type (such as int and String) or Generic types (such as List<Integer>).

Example:

The following method signature accepts a parameter of type List<Integer>:

<T> void myMethod(List<T> myList)

Return type:

Generic methods can also have a generic return type.

Example:

The following method signature returns a list of type List<String>:

<T> List<T> myMethod()

Practical case:

add() method in LinkedList class

java.util.LinkedListadd in class The () method is a generic method that allows various types of elements to be added to the end of the linked list. Its signature is as follows:

public boolean add(E e)

where E is a generic type variable representing the type of elements that can be added to the linked list. The add() method accepts a parameter of type E and adds it to the end of the linked list.

By using generics, the add() method can handle elements of various types without having to write dedicated type-specific methods.

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