In this video we are going to learn generic concept in java. what is generic and how it is important for code.
Crash Courses Playlist : https://www.youtube.com/playlist?list=PL0zysOflRCenCfUTpsGw9crgOih-VbNoT Generic in one video | Java Generic Full concept in 23 min in Hindi
Exmaple.java
import java.util.*;
public class Demo {
public static void main(String[] args) {
List<Integer> list = new ArrayList<>();
// list.add("LCWD");
list.add(123);
List anotherList = new ArrayList();
anotherList.add("LCWD");
anotherList.add(12);
anotherList.add(12.12);
System.out.println(list);
System.out.println(anotherList);
}
}
Box.java
public class Box<T> {
// Object class is top most parent class of all java classes
T container;
public Box(T container) {
this.container = container;
}
public void performSomeTask() {
if (container instanceof String) {
System.out.println("length of " + container + " is " + (((String) this.container).length()));
} else if (container instanceof Integer) {
System.out.println("This is integer value " + container);
}
}
public Object getValue() {
return this.container;
}
}
Example.java
import javax.swing.SpinnerDateModel;
public class Example {
public static void main(String[] args) {
Box<String> box = new Box<>("Wow this is amazing");
System.out.println(box.getValue());
System.out.println(box.container.getClass().getName());
Box<Integer> box1 = new Box<>(121);
System.out.println(box1.getValue());
System.out.println(box1.container.getClass().getName());
box.container = "subscribe to youtube channel";
box1.container = 1452;
Box<Boolean> box2 = new Box<>(true);
System.out.println(box2.getValue());
box.performSomeTask();
box1.performSomeTask();
}
}