Types of generics in java

Java generic type method

// generic methods

public <T> List<T> fromArrayToList(T[] a) {   
	    return Arrays.stream(a).collect(Collectors.toList());
	}

public static <T, G> List<G> fromArrayToList(T[] a, Function<T, G> mapperFunction) {
	    return Arrays.stream(a)
	      .map(mapperFunction)
	      .collect(Collectors.toList());
	}

// bounded generics

public <T extends Number> List<T> fromArrayToList(T[] a) {
	    ...
	}

//multiple bounds

<T extends Number & Comparable>

// upper bound wildcards

public static void paintAllBuildings(List<? extends Building> buildings) {
	    ...
	}
    
// lower bound wildcard

<? super T>

Source: baeldung.com

Java generics type

Java Generic Type Naming convention helps us understanding code easily and having a naming convention is one of the best practices of Java programming language. So generics also comes with its own naming conventions. Usually, type parameter names are single, uppercase letters to make it easily distinguishable from java variables. The most commonly used type parameter names are:

E – Element (used extensively by the Java Collections Framework, for example ArrayList, Set etc.)
K – Key (Used in Map)
N – Number
T – Type
V – Value (Used in Map)
S,U,V etc. – 2nd, 3rd, 4th types

Source: grepper.com

Similar codes

0 vote325 views1 answer
Javafx application fxml
Java
49 votes330 views6 answers
Char array to string java
Java
0 vote334 views1 answer
Kano magic wand
Java
0 vote294 views1 answer
Android studio reg get float from numeric string
Java
0 vote380 views1 answer
Spring valid request body custom message
Java Spring
-2 votes322 views1 answer
Enhanced for-loop,
Java
0 vote322 views2 answers
Android httpurlconnection post multipart/form-data
Java
3 votes321 views1 answer
How to get data from radio group in android
Java
3 votes355 views1 answer
How to initialize bigdecimal in java
Java
4 votes357 views2 answers
How to create a gui in java
Java