Java tutorials

Java tutorials

• 1.
  Classes https://docs.oracle.com/javase/tutorial/java/concepts/class.html class Bicycle {CLASS int cadence = 0; int speed = 0; INITIAL INTEGERS int gear = 1; void changeCadence(int newValue) { cadence = newValue; } void changeGear(int newValue) { gear = newValue; } DECLARING TO INTEGERS void speedUp(int increment) { speed = speed + increment; } void applyBrakes(int decrement) { speed = speed - decrement; } void printStates() { System.out.println("cadence:" + cadence + " speed:" + PRINT OUT speed + " gear:" + gear); } } Inheritance https://docs.oracle.com/javase/tutorial/java/concepts/inheritance.html class MountainBike extends Bicycle { // new fields and methods defining // a mountain bike would go here Can inherit traits from other forms of bikes }
• 2.
  Interfaces https://docs.oracle.com/javase/tutorial/java/concepts/interface.html Bicycle as Interface interfaceBicycle { // wheel revolutions per minute void changeCadence(int newValue); void changeGear(int newValue); void speedUp(int increment); void applyBrakes(int decrement); }
• 3.
  Implementing Interface mustinclude: the methods (changeGear, changeCadence, speedUp, applyBrakes, etc) class BRANDBicycle implements Bicycle { int cadence = 0; int speed = 0; INITIAL VARIABLE int gear = 1; // The compiler will now require that methods // changeCadence, changeGear, speedUp, and applyBrakes // all be implemented. Compilation will fail if those // methods are missing from this class. void changeCadence(int newValue) { cadence = newValue; } void changeGear(int newValue) { gear = newValue; } void speedUp(int increment) { speed = speed + increment; } void applyBrakes(int decrement) { speed = speed - decrement; } void printStates() { System.out.println("cadence:" + cadence + " speed:" + speed + " gear:" + gear); } }
• 4.
  Questions 1. Real-world objectscontain State and Behaviour. 2. A software object's state is stored in ___. 3. A software object's behaviour is exposed through ___. 4. Hiding internal data from the outside world and accessing it only through publicly exposed methods is known as data ___. 5. A blueprint for a software object is called a ___. 6. Common behaviour can be defined in a ___ and inherited into a ___ using the ___ keyword. 7. A collection of methods with no implementation is called a ___. 8. A namespace that organizes classes and interfaces by functionality is called a ___. 9. The term API stands for ___?