Chapter 1 Fundamentals of Java Progra m ming By Ms.Ramsha Sohail

1. Chapter1 Fundamentals ofJava Programming By Ms.Ramsha Sohail

2. Computers and ComputerProgramming • Writing and Executing a JavaProgram • Elements of a JavaProgram • Features ofJava • Accessing the Classes and Class Members • The Memory Usage by a JavaProgram • When Will the ErrorOccur?

3. Understand how computers and computer programswork. • Understand how a Java program iswritten, • compiled, andexecuted. • Understand what makes Java platform independent. • Identify the object-oriented features of Java. • Identify different elements of a Java program: primitive variable, reference variable, local variable, instance variable, method, and class.

4. Identify where in memory the method invocations, objects, and variablesare stored. • Understand how access modifiers define the accessibility of classes and class members. • Understand the concepts of early binding and late binding in the context ofprogram errors.

5. How a ComputerWorks How a Computer ProgramWorks

6. From a computer program’s perspective, a computer consists of components to dothe following: • Receive data from auser • Process the data according to instructions froma program or auser • Place the resultssomewhere

7. Places to Store Data: • Permanent storage: harddrive • Temporary storage:RAM • I/O Devices: monitor, keyboard, disk, and printer • CPU: The Brain of theComputer

9. Computers and ComputerProgramming • Writing and Executing a JavaProgram • Elements of a JavaProgram • Features ofJava • Accessing the Classes and Class Members • The Memory Usage by a JavaProgram • When Will the ErrorOccur?

10. A compiler translates a program in C/C++ to a binary format called executablecode • The executable code is machine dependent • Java programs are machine independent, thanks to Javavirtual machine(JVM).

11. Writing a JavaProgram • Compiling a JavaProgram • Executing a JavaProgram

12.  Source code: a set of instructions in text format written according to the rules ofthe Java programminglanguage.  Source file: contains these instructions, and has the file extension .java

13. Machine language: a binaryformat • In Java, the compiler compiles the source code intobytecode • To create the bytecode files (.class) from the source fileRobotManager.java: • javacRobotManager.java

14. Executing a Java program by issuingthe • javacommand: • java RobotManager Ginny420 • The JVM reads the bytecode file and translates the instructions to the executable format that your computercan understand

16. Computers and ComputerProgramming • Writing and Executing a JavaProgram • Elements of a JavaProgram • Features ofJava • Accessing the Classes and Class Members • The Memory Usage by a JavaProgram • When Will the ErrorOccur?

17. Classes andObjects • Methods • Variables and DataTypes • Execution Flow of aProgram

18. A class is a template (or a blueprint) from which objects arecreated • Writing a class is called implementing a class: declaration &body • An object is instantiated from a class, and also called the instance of thatclass • Each object has a state, a set of characteristics, and a behavior represented bymethods

20. The state of an object is represented by a set of data items that are handled byusing variables • The variable’s type determines whatkind • of values it canhold • The declaration of avariable: • <type> <name>; • An object reference variable refer to an object: • Robotrobot;

21. Expressions: combination of variables, operators, literals, and methodcalls • Statements: a complete execution unitof • a program; contain one ormore expressions • Blocks: a group of zero ormore • statements between an opening braceand a closingbrace • Execution Flow Control: skip, execute,or • repeatedly execute a block ofstatements

22. Computers and ComputerProgramming • Writing and Executing a JavaProgram • Elements of a JavaProgram • Features ofJava • Accessing the Classes and Class Members • The Memory Usage by a JavaProgram • When Will the ErrorOccur?

23. PlatformIndependence • Object-OrientedProgramming

24. “write once, runanywhere.” • The Java compiler compiles the source code into bytecode, which can be interpreted by a suitable JVM on any platform • The JVM can prevent the code from generating side effects outside thesystem.

25. Encapsulation: combining an object’s data with itsmethods • Inheritance: • Codereusability • Codemaintenance • ImplementingOOP • Polymorphism: allows an object of a superclass to refer to an object ofany • subclass.

26. Computers and ComputerProgramming • Writing and Executing a JavaProgram • Elements of a JavaProgram • Features ofJava • Accessing the Classes and Class Members • The Memory Usage by a JavaProgram • When Will the ErrorOccur?

27. Class members: variables, methods, and nestedclasses. • Access modifiers: control the access to the classmembers • public • protected • default • private

28. Computers and ComputerProgramming • Writing and Executing a JavaProgram • Elements of a JavaProgram • Features ofJava • Accessing the Classes and Class Members • The Memory Usage by a JavaProgram • When Will the ErrorOccur?

30. Computers and ComputerProgramming • Writing and Executing a JavaProgram • Elements of a JavaProgram • Features ofJava • Accessing the Classes and Class Members • The Memory Usage by a JavaProgram • When Will the ErrorOccur?

31. Compilationfails • An exception is thrown atruntime