OOP - Lecture02 - Introduction to Java.pptx
- 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.
- 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?