Generics method in java

The methods which can handle different types of arguments are known as generic methods. Types of the argument are specified on method call.

Syntax: generic method includes a type parameter, inside angle brackets and appears before the method’s return type.

public static <T> T identical(T obj){
        return returnValue;
 }

Example:

GenericsTest.java

/**
 * This class is used to show the use of generics method.
 * @author w3spoint
 */
class Test {
  //Generics method
  public <T> void showItemDetails(T item){
	  System.out.println("Value of the item: " + item);
	  System.out.println("Type of the item: " 
			  + item.getClass().getName());
  }
}
 
public class GenericsTest {	
	public static void main(String args[]){
		//String type test
		Test test = new Test();
		test.showItemDetails("Test String.");
		test.showItemDetails(100);
	}
}

Output:

Value of the item: Test String.
Type of the item: java.lang.String
Value of the item: 100
Type of the item: java.lang.Integer

Download this example.

Generics method example with two parameters:

GenericsTest.java

/**
 * This class is used to show the use of 
 * generics method with two parameters.
 * @author w3spoint
 */
class Test {
  //Generics method with two parameters.	
  public <T, U> void showItemDetails(T itemT, U itemU){
	  System.out.println("Value of the itemT: " + itemT);
	  System.out.println("Type of the itemT: " 
			  + itemT.getClass().getName());
	  System.out.println("Value of the itemU: " + itemU);
	  System.out.println("Type of the itemU: " 
			  + itemU.getClass().getName());
  }
}
 
public class GenericsTest {	
	public static void main(String args[]){
		//String type test
		Test test = new Test();
		test.showItemDetails("Test String.", 100);
	}
}

Output:

Value of the itemT: Test String.
Type of the itemT: java.lang.String
Value of the itemU: 100
Type of the itemU: java.lang.Integer

Download this example.

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