First session in android using java start with intoduction to java and why we need it for android development.

1. ANDROID COURSE
WITH JAVA
Developed by Keroles Magdy
keroles.m.yacoub@gmail.com
2019 ©

2. Welcome !

3. Steps & Rules

4. Difference of this course
• Best practice for each topic.
• Simple project in every session.
• Problem solving.
• Latest technology.

5. Session topics :-
• Binary system & Machine language.
• Meaning of programing.
• What is java?.
• JDK, JRE and JVM.
• Tools & Setups.
• Interpreter & Compiler.
• Hello java program.
• Data Types & Variables.
• Keywords & Comments.
• Operators.

6. Binary system & Machine language:-
• Binary system uses only two symbols: typically "0" (zero) and "1" (one).
• "binary" comes from "Bi-" meaning two, like "bi-" in words such as
"bicycle" (two wheels) or "binocular" (two eyes).
• Machine language is the only language a computer is capable of
understanding.
• 01001000 01100101 01101100 01101100 01101111 00100000 01010111
01101111 01110010 01101100 01100100
Hello World

7. Meaning of programing :-
• process of designing and building an executable computer program
Problem
Definition
Problem
Analysis
Coding &
Documentation
Testing &
Debugging
Maintenance

8. What is java? :-
• Java is a programming language first released by Sun
Microsystems in 1995. Java is fast, secure, and reliable. From
laptops to datacenters, game consoles to scientific supercomputers,
cell phones to the Internet.
Java is everywhere!

9. JDK, JRE and JVM :-
+
+
JDK
Dev
Tools
JRE
+
Lib Files
JVM

10. JDK, JRE and JVM :-
• JDK, ( Java Development Kit ) provides environment to develop and
run the Java programs.
• Note : JDK is only used by Java Developers.
• JRE, (Java Runtime Environment) is an environment to run program
which are already developed.
• JVM, (Java Virtual machine) is responsible for executing the java
program line by line hence it is also known as interpreter.

11. Tools & Setups :-
• https://www.oracle.com/technetwork/java/javase/downloads/jdk13-
downloads-5672538.html
• https://www-eu.apache.org/dist/netbeans/netbeans/11.1/Apache-
NetBeans-11.1-bin-windows-x64.exe

12. Interpreter & Compiler :-
• Interpreter, is a computer program, which coverts each high-level
program statement into the machine code.
• Convert code into machine code when the program is run.
InterpreterSource Code Output

13. Interpreter & Compiler :-
• Compile, will convert the code into machine code (create an exe)
before program run.
• Cannot fix errors found in that program.
CompilerSource Code OutputMachine Code

14. Break

15. Hello java program :-
• Code :
• Output :
• Hello, World!

16. Hello java program :-
• Package, group of classes.
• Class, consist of method and variable.
• Function, a set of instructions that perform a task.
• Method, a set of instructions that are associated with an object.

17. Data Types & Variables :-
• Primitive datatypes, are predefined by the language and named by a
keyword.
• EX : ( boolean, char, byte, short, int, long, float and double ).
• Non- Primitive datatypes, (Reference Datatypes) created using
defined constructors of the classes.
• EX : ( Classes, Arrays and String ).

18. Data Types & Variables :-
• Size in memory.
Data Type Default size
boolean 1 bit
char 2 byte
byte 1 byte
short 2 byte
int 4 byte
long 8 byte
float 4 byte
double 8 byte

19. Data Types & Variables :-
• In java syntax
boolean myBool = true; // true or false
byte a = 68; // -128 to 127
short myNum = 5000; // -32768 to 32767
int myNum = 5; // -2147483648 to 2147483647
long myNum = 15000000000L; // -9223372036854775808
float myNum = 5.75f; // 3.4e−038 to 3.4e+038
double myNum = 19.99d; // 1.7e−308 to 1.7e+308
char a = ‘A’;
String myText = "Hello";

20. Data Types & Variables :-
• Variables, is a container which holds the value while the java
program is executed.
• Types : (local variable - instance variable - static variable ).
• Local Variable, A variable declared inside the body of the method.
• Instance Variable, A variable declared inside the class but outside the
body of the method.
• Static variable, share among all the instances of the class. Memory
allocation for static variable happens only once when the class is
loaded in the memory.

21. Keywords & Comments :-
• Keywords, are also known as (reserved words). They are particular
words which acts as a key to a code
• EX : ( abstract-boolean-break-class-return )
• Comments, are statements that are not executed by the compiler and
interpreter. Used to explanation about the variable, method, class
• Types :
1) Java Single Line Comment ( // )
2) Java Multi Line Comment ( /**/ )
3) Java Documentation Comment ( /***/ )

22. Operators :-
• Unary Operator. ( postfix, prefix )
• Arithmetic Operator. ( *, / ,% , +, -)
• Relational Operator. ( <, >, <=, >=, ==, !=, instanceof )
• Logical Operator. ( &&, ||)
• Ternary Operator.
• Assignment Operator. ( =, +=, -=, *=, /=, %=)

23. the End