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[java/en] Merged definitions of abstract and added final

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Merged definitions of abstract and added a definition of final classes.
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Zachary Ferguson
2015-10-06 18:28:57 -04:00
parent da10a0bf06
commit 93d7d801d8
1 changed files with 31 additions and 23 deletions
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@@ -513,14 +513,9 @@ public class ExampleClass extends ExampleClassParent implements InterfaceOne,
} }
} }
<<<<<<< HEAD
// There are also two special types of classes, abstract and final. // There are also two special types of classes, abstract and final.
// Marking a class as abstract means that it contains abstract methods that must
// be defined in a child class. Similar to interfaces, abstract classes cannot
// be instantiated, but instead must be extended and the abstract methods
// defined. Different from interfaces, abstract classes can contain a mixture of
// concrete and abstract methods.
public abstract class Mammal() public abstract class Mammal()
{ {
// Abstract classes can contain concrete methods. // Abstract classes can contain concrete methods.
@@ -539,17 +534,6 @@ public abstract class Mammal()
public abstract String getBinomialNomenclature(); public abstract String getBinomialNomenclature();
} }
// Final classes are classes that cannot be inherited from and are therefore a
// final child. In a way, final classes are the opposite of abstract classes
// because abstract classes must be extended, but final classes cannot be
// extended.
public final class SaberToothedCat extends Mammal
{
public String getBinomialNomenclature()
{
return "Smilodon fatalis";
}
=======
// Abstract Classes // Abstract Classes
// Abstract Class declaration syntax // Abstract Class declaration syntax
@@ -558,10 +542,13 @@ public final class SaberToothedCat extends Mammal
// // Method declarations // // Method declarations
// } // }
// Methods can't have bodies in an interface, unless the method is // Marking a class as abstract means that it contains abstract methods that must
// static. Also variables are NOT final by default, unlike an interface. // be defined in a child class. Similar to interfaces, abstract classes cannot
// Also abstract classes CAN have the "main" method. // be instantiated, but instead must be extended and the abstract methods
// Abstract classes solve these problems. // defined. Different from interfaces, abstract classes can contain a mixture of
// concrete and abstract methods. Methods in an interface cannot have a body,
// unless the method is static, and variables are final by default, unlike an
// abstract class. Also abstract classes CAN have the "main" method.
public abstract class Animal public abstract class Animal
{ {
@@ -578,7 +565,7 @@ public abstract class Animal
// No need to initialize, however in an interface // No need to initialize, however in an interface
// a variable is implicitly final and hence has // a variable is implicitly final and hence has
// to be initialized. // to be initialized.
private int age; protected int age;
public void printAge() public void printAge()
{ {
@@ -615,7 +602,28 @@ class Dog extends Animal
pluto.eat(); pluto.eat();
pluto.printAge(); pluto.printAge();
} }
>>>>>>> adambard/master }
// Final Classes
// Final Class declaration syntax
// <access-level> final <final-class-name> {
// // Constants and variables
// // Method declarations
// }
// Final classes are classes that cannot be inherited from and are therefore a
// final child. In a way, final classes are the opposite of abstract classes
// because abstract classes must be extended, but final classes cannot be
// extended.
public final class SaberToothedCat extends Animal
{
// Note still have to override the abstract methods in the
// abstract class.
@Override
public void makeSound()
{
System.out.println("Roar");
}
} }
``` ```