Et eksempel fra Universitet el. Videregående 3. år
Noter til Java Programmering
Se, hvordan en færdig opgave er bygget op. Brug den til at forstå form, struktur og faglige valg.
Om opgaven
Opgaven er skrevet af en elev i Universitet el. Videregående 3. år i Andet og fylder 124 sider. Navne og andre personoplysninger er fjernet. Brug den til at se, hvordan opgaven er bygget op, og hvilke valg eleven har truffet undervejs. Den kan ikke afleveres som din egen: teksten ligger åbent på nettet og fanges af plagiatkontrollen.
Opgavens overskrifter
- Kapitel 1 Klasser og Objekter
- Objekt Model
- Klasse begrebet
- Klasser og objekter
- Skabelse af objekter
- new operatoren
- null Referencen
- Tildeling af objekt reference
- Definering af en klasse
- Metode og variable modifiers
- Class modifiers
- Instanse Variabler
- Definering af Instanse Metoder
- Indkapsling
- Constructors
- Definering af Constructors
- Definering af
- this-Referencen
- this Referencen
- Overloading
- Værdioverførsel til metoder
- Værdioverførsel
- Overførsel af referencer til metoder
- Overloading Constructors
- Sammenhæng mellem Constructors
Uddrag fra opgaven
Kapitel 1 Klasser og Objekter
Objekt Model
Object orientation is all about modelling real world objects or concepts in software. Java is an ideal language for doing this. In fact, unlike some languages like C and C++, it forces you to think in an object-oriented way, since every piece of Java code must be contained within a class definition. Most of the examples we will use are based around a car. In the real world, we create a design for a car, take some raw materials and follow the design to create our finished object (then drive away in it!). In our software world, we will create our design (the Java class), take some memory and form our object(s) out of it.
Of course, we ourselves don’t manufacture these objects ourselves; we define the features of an object in a class definition and then get Java (the "object factory") to create objects of this class for us.
Klasse begrebet
Klasse begrebet
A class is a template for building multiple objects with similar features. A class encapsulates all the features of an object, i.e. its data structure and its behaviour. So, when you write an object-oriented program, you don't write code for individual objects. Instead, you define the data structure and the behaviour (or operations) of a class of objects. Then, when you want to create objects of this class, you get Java to create instances of this class. All objects of the same class have the same data structure and behaviour (as defined in the class), but each object is independent of every object of its class. In other words, each object can store its own values in the data structure defined by the class.
Klasser og objekter
Klasser og objekter
A class is a template for building objects of that class. In object-oriented terminology, an object is an instance of a class. This simply means that each object of that class has the same data structure and operations. However, the values held in this data structure are unique to each object. Such data is therefore called instance data. Furthermore, the operations of an object act on that object's instance data.
Skabelse af objekter
Skabelse af objekter
Objects are created by using the new operator with the class of the object and any arguments needed by the class' constructor.
Uddraget er læst maskinelt fra elevens PDF, så enkelte ord kan stå forkert. Hele opgaven står herunder.