What is Generic programming?
Generics were introduced into Java in JDK 5.0. Generics incorporate stability to your code by making bugs detectable at compile time. Generic is a class or interface that deals in parametrized type. Generics enable developers to write more general and reusable Classes, Interfaces and methods. The essence of Generics is type safety. Programs can get infected by various bugs which will surface only at run time, without type safety.
Benefits of Generic programming
- Strong type checking at compile time
- Removing type casting
- Enabling programmers to write safe, general, reusable and more readable code
- Generics add stability to code by making bugs detectable at compile time
Example:
import java.util.LinkedList;
public class GenricsTest {
public static void main(String[] args) {
LinkedList list=new LinkedList();
list.add(12);//Without Genrics
int i=(int)list.get(0);//Type
casting required
LinkedList<Integer> list1=new LinkedList();
list1.add(12);//With generics
int i1=list1.get(0);//No need
of type casting
}
}
Example: Writing a general Type
class Rectangle<T>{//
General Rectangle type
T h;
T w;
public Rectangle(T h, T w) {
super();
this.h = h;
this.w = w;
}
}
class Util{
public static <T> void displayRectangle(Rectangle r)//generic
method
{
System.out.println("h="+r.h+"
w="+ r.w);
}
}
public class GenericsDemo {
public static void main(String[] args) {
Rectangle<Integer> rint=new Rectangle<Integer>(12,20);//object-1
Rectangle<Float> rfloat=new Rectangle<Float>(30.6f,23.5f);//object-2
Util.<Integer>displayRectangle(rint);
Util.<Float>displayRectangle(rfloat);
}
}
Output:
h=12 w=20
h=30.6 w=23.5
