It is introduction of java for beginners

1. Lecture 02
Introduction to Java

2. Lecture Outline
• Evolution of Programming Languages
• Why Java?
• Java History
• Java Versions
• Java Features
• Java Procedure
• Revision of Programming Fundamentals Topics

3. What is a Program?
• A computer program is a sequence of instructions written to
perform a specified task for a computer.

4. The Evolution of Programming Language
• Machine Language: 1940’s
• Assembly Language: Early 1950’s
• Higher-Level Languages: Late 1950’s
• Fortran: scientific computation
• COBOL: business data processing
• Lisp: symbolic computation
• Today: Thousands of programming languages available

5. What is Programming?
• When we say “programming” we are actually referring to the
science of transforming our intentions in a high-level
programming language.

6. What is this course about?
• Learn programming in a high-level programming language.
• Programming has many paradigms
• Procedural
• Object-Oriented
• We will study Object-Oriented Programming using ‘Java’, a
popular high-level object-oriented programming language.

7. Non-structured Programming
e.g. Assembly Language, BASIC
• Advantages
– Low Level access
– High Optimization
– Shorter size programs
• Disadvantages
– Large programs highly complex
– Difficult to understand
– Repetition of code
a 100
mov ax,0002
mov bx,0004
add ax,bx
nop

8. Procedural/Structured Programming
e.g. C, Pascal
• Advantages
– Fast execution
– Small memory footprint (Size)
• Disadvantages
– Limited in Enhancement over the time
– Low reusability
– Difficult to Extended
– Less Dynamic architecture

9. Object Oriented Programming
e.g. C++, C#, Java etc
• Disadvantages
– Little Slow execution
– Little Big memory footprint (Size)
• Advantages
– Better Enhancement over the time
– High reusability
– Easy to Extended
– Better representation of real world problems

10. Why Java?
• It’s the current “hot” language
• Java mean “Cup of Coffee”
• It’s almost entirely object-oriented
• It has a vast library of predefined objects and operations
• It’s more platform independent
• This makes it great for web programming too (but that is beyond this
course)
• It’s more secure
• It isn’t C++

11. Java History (1 of 3)
• created in 1991
• by James Gosling et al. of Sun Microsystems.
• Initially called Oak, in honor of the tree outside Gosling's window,
its name was changed to Java because there was already a
language called Oak.

12. Java History (2 of 3)
• The term Java actually refers to more than just a particular
language like C or Pascal. Java encompasses several parts,
including:
• A high level language – Java language is a high level one that at a
glance looks very similar to C and C++ but offers many unique features
of its own.
• Java bytecode – A compiler, such as Sun's javac, transforms the Java
language source code to bytecode that runs in the JVM.
• Java Virtual Machine (JVM) – a program, such as Sun's java, that runs
on a given platform and takes the bytecode programs as input and
interprets them just as if it was a physical process executing machine
code.

13. Java History (3 of 3)
• Sun provides a set of programming tools such as javac, java and
others in a bundle that it calls a Java Software Development Kit
for each version of the language for different platforms such as
Windows, Linux, etc.
• Sun also provides a runtime bundle with just the JVM when the
programming tools are not needed.

14. Java Versions (1 of 2)
• Since its introduction in 1995, Sun has released a new version of the
Java language every two years or so.
• These new versions brought enhancements, new capabilities and fixes to
bugs.
• Till 2002, the versions were numbered 1.x, where x reached up till 4.
(Intermediate revisions were labeled with a third number - 1.x.y - as in
1.4.2.)
• After that all the versions were released with a whole number such as 5.0 or
6.
• The current version of Java is Java SE 17 (LTS) where SE refers to
Standard Edition (used for targeting workstations) and the LTS refers to
Long Term Support.
• Not all Java versions have LTS, so far only 3 have been released (2008,
2018 and 2021)
• Another newer version of Java SE 18 is expected to be released in
March 2022

15. Java Versions (2 of 2)
• The major editions of Java are:
• Java Card (for smart cards)
• Java Micro Edition (for limited resources environments)
• Java Standard Edition (for workstations)
• Java Enterprise Edition (for enterprises and internet environments)

16. Java Features
• Simple & Secure
• Object-Oriented
• Robust
• Restricts the programmer to find the mistakes early
• Performs compile-time (strong typing) and run-time (exception-handling)
checks
• Manages memory automatically
• Multithreaded
• Architecture-Neutral
• Interpreted and High-Performance
• Distributed
• Dynamic

17. Java Procedure
• The essential steps to creating and running Java programs go as
follows:
• Create a Java source code file
• Compile the source code
• Run the compiled code in any Java Virtual Machine.

18. Java Program Execution

19. Java Program Execution
• Manual – with text editor (notepad)
• Create the Java source code files (*.java)
• Use Command Line tools in the Java Software Development Kit (SDK).
• The SDK is provided by Sun for several platforms and includes a
number of tools, the most important of which are:
• javac – compiles Java source code files
• java – runs Java application programs
• appletviewer – tests applets independently of a browser
• Integrated Development Environment (IDE)
• NetBeans
• Borland JBuilder
• Eclipse
• Dr Java
• IntelliJ IDEA (My Favorite)

20. Revision (1 of 3)
• Decision Making Statements
• If-else
• Switch Case
• Loops
• For
• While
• Do-While
• Nested {{}}

21. Revision (2 of 3)
• Variables
• Strings in C/C++
• Arrays
• 1D
• 2D
• ND

22. Revision (3 of 3)
• Functions / Methods
• Declaration
• Definition
• Calling
• Overloading
• Passing Arguments
• By Value
• By reference in java?

23. Thank You 
Any Questions?