basic java for android developer
DESCRIPTION
Getting Starts Basic java for Android DeveloperTRANSCRIPT
Basic JAVA for Android Development
Nattapong Tonprasert
Reference
• Head First Java, O'Reilly
Introduction
The Way Java Works
Installation Java Platform (JDK)
• Download : http://www.oracle.com/technetwork/java/javase/downloads/index.html
Look how easy it is to write java
Look how easy it is to write java
Code structure in Java
Code structure in Java
source file
class file
method 1 statement
method 2 statement
Code structure in Java
public class Dog { !!!!}
class
public class Dog { void bark () { !! } }
method
public class Dog { void bark () { statement1;!! ! statement2; } }
statements
Anatomy of a class
Writing a class with a main
public class MyFirstApp {! public static void main (String[] args) { System.out.println("I Rule!"); System.out.println("The World!"); } }
Statements
int x = 3;String name = "Dirk";x = x * 17;System.out.print("x is " + x);double d = Math.random();// this is a comment
Conditionif (x == 10) { System.out.println("x must be 10");} else { System.out.println("x isn't 10");}!if ((x < 3) && (name.equals("Dirk"))) { System.out.println("Gently");}!if ((x < 3) || (name.equals("Dirk"))) { System.out.println("Gently");}
Looping
while (x > 12) { x = x - 1; System.out.println("x is " + x);}!for (x = 0; x < 10; x = x + 1) { System.out.println("x is " + x);}
Classes and Objects
Classes and Objects
Classes and Objects
Classes and Objects
thinking about objects
When you design a class, think about the objects that will be created from that class type. Think about
• things the object knows
• things the object does
thinking about objects
What’s the difference between a class and an object?
• A class is not an object (but it’s used to construct them)
• A class is a blueprint for an object
Encapsulation
• public
• private - self class
• protected - self package
Class GoodDogclass GoodDog { private int size; public int getSize() { return size; } public void setSize(int s) { size = s; } void bark() { if (size > 60) { System.out.println("Woof! Woof!"); } else if (size > 14) { System.out.println("Ruf! Ruf!"); } else { System.out.println("Yip! Yip!"); } }}
GoodDog Test Drive
public class GoodDogTestDrive { public static void main (String[] args) { GoodDog one = new GoodDog(); one.setSize(70); GoodDog two = new GoodDog(); two.setSize(8); System.out.println("Dog one: " + one.getSize()); System.out.println("Dog two: " + two.getSize()); one.bark(); two.bark(); }}
Static variables
Static variables
Static variables
class Player { static int playerCount = 0; private String name;! public Player(String n) { name = n; playerCount++; }}!public class PlayerTestDrive { public static void main(String[] args) { System.out.println(Player.playerCount); Player one = new Player("Tiger Woods"); System.out.println(Player.playerCount); }!}