La herencia es un pilar importante de OOP (Programación Orientada a Objetos). Es el mecanismo en java por el cual una clase puede heredar las características (campos y métodos) de otra clase.
Terminología importante:
Java
// Java program to illustrate the
// concept of inheritance
// base class
class Bicycle {
// the Bicycle class has two fields
public int gear;
public int speed;
// the Bicycle class has one constructor
public Bicycle(int gear, int speed)
{
this.gear = gear;
this.speed = speed;
}
// the Bicycle class has three methods
public void applyBrake(int decrement)
{
speed -= decrement;
}
public void speedUp(int increment)
{
speed += increment;
}
// toString() method to print info of Bicycle
public String toString()
{
return ("No of gears are " + gear + "\n"
+ "speed of bicycle is " + speed);
}
}
// derived class
class MountainBike extends Bicycle {
// the MountainBike subclass adds one more field
public int seatHeight;
// the MountainBike subclass has one constructor
public MountainBike(int gear, int speed,
int startHeight)
{
// invoking base-class(Bicycle) constructor
super(gear, speed);
seatHeight = startHeight;
}
// the MountainBike subclass adds one more method
public void setHeight(int newValue)
{
seatHeight = newValue;
}
// overriding toString() method
// of Bicycle to print more info
@Override public String toString()
{
return (super.toString() + "\nseat height is "
+ seatHeight);
}
}
// driver class
public class Test {
public static void main(String args[])
{
MountainBike mb = new MountainBike(3, 100, 25);
System.out.println(mb.toString());
}
}
Java
// Java program to illustrate the
// concept of single inheritance
import java.io.*;
import java.lang.*;
import java.util.*;
class one {
public void print_geek()
{
System.out.println("Geeks");
}
}
class two extends one {
public void print_for() { System.out.println("for"); }
}
// Driver class
public class Main {
public static void main(String[] args)
{
two g = new two();
g.print_geek();
g.print_for();
g.print_geek();
}
}
Java
// Java program to illustrate the
// concept of Multilevel inheritance
import java.io.*;
import java.lang.*;
import java.util.*;
class one {
public void print_geek()
{
System.out.println("Geeks");
}
}
class two extends one {
public void print_for() { System.out.println("for"); }
}
class three extends two {
public void print_geek()
{
System.out.println("Geeks");
}
}
// Drived class
public class Main {
public static void main(String[] args)
{
three g = new three();
g.print_geek();
g.print_for();
g.print_geek();
}
}
Java
// Java program to illustrate the
// concept of Hierarchical inheritance
class A {
public void print_A() { System.out.println("Class A"); }
}
class B extends A {
public void print_B() { System.out.println("Class B"); }
}
class C extends A {
public void print_C() { System.out.println("Class C"); }
}
class D extends A {
public void print_D() { System.out.println("Class D"); }
}
// Driver Class
public class Test {
public static void main(String[] args)
{
B obj_B = new B();
obj_B.print_A();
obj_B.print_B();
C obj_C = new C();
obj_C.print_A();
obj_C.print_C();
D obj_D = new D();
obj_D.print_A();
obj_D.print_D();
}
}
Java
// Java program to illustrate the
// concept of Multiple inheritance
import java.io.*;
import java.lang.*;
import java.util.*;
interface one {
public void print_geek();
}
interface two {
public void print_for();
}
interface three extends one, two {
public void print_geek();
}
class child implements three {
@Override public void print_geek()
{
System.out.println("Geeks");
}
public void print_for() { System.out.println("for"); }
}
// Drived class
public class Main {
public static void main(String[] args)
{
child c = new child();
c.print_geek();
c.print_for();
c.print_geek();
}
}
Java
public class SolarSystem {
}
public class Earth extends SolarSystem {
}
public class Mars extends SolarSystem {
}
public class Moon extends Earth {
}
Java
class SolarSystem {
}
class Earth extends SolarSystem {
}
class Mars extends SolarSystem {
}
public class Moon extends Earth {
public static void main(String args[])
{
SolarSystem s = new SolarSystem();
Earth e = new Earth();
Mars m = new Mars();
System.out.println(s instanceof SolarSystem);
System.out.println(e instanceof Earth);
System.out.println(m instanceof SolarSystem);
}
}
Publicación traducida automáticamente
Artículo escrito por GeeksforGeeks-1 y traducido por Barcelona Geeks. The original can be accessed here. Licence: CCBY-SA