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 vote378 views1 answer
Itext new page
Java
2 votes361 views4 answers
Change color of action bar android studio
Java
12 votes323 views1 answer
Get certain character from string java
Java
0 vote417 views2 answers
Spring boot base url
Java Spring
0 vote331 views1 answer
Offsetdatetime to date
Java
0 vote338 views1 answer
Delet file from path android
Java
6 votes332 views3 answers
Initialize arraylist
Java
0 vote325 views1 answer
Get device id programmatically android
Java
0 vote278 views1 answer
Super vs super()
Java
0 vote312 views1 answer
Inline intent to jump new activity
Java