PROGRAMMING
LANGUAGE FUNDAMENTALS
Java Programming
CPEPROG – MODULE 2A
TOPICS:
Java Programming with Netbeans IDE
Coding Conventions and Data Types
Java Output and Input
Java Operators
Math Functions
Control and Iterative Statement
Characters and String
Arrays
Attributes, Methods and Constructions
FUNDAMENTAL CONCEPTS
Programming Terminologies
PROGRAM
Set of written instruction
MACHINE LANGUAGE
Most basic circuitry-level language
HIGH-LEVEL PROGRAMMING LANGUAGE
syntax are close to human language
INTEGRATED DEVELOPMENT ENVIRONMENT (IDE)
Software application that facilitates software development
FUNDAMENTAL CONCEPTS
Programming Terminologies
SYNTAX
Rules of language / Arrangement
COMPILER OR INTERPRETER
Translate language statements into machine code
DEBUGGING
Process of identifying and removing Errors
Syntax Error and Logic Errors
JAVA PROGRAMMING
Java Programming
isa computer programming language that allows
programmers to write computer instructions using English
based commands
It’s known as a “high-level” language
JAVA PROGRAMMING
Java Programming
Developed in early 1990s by James Gosling et. al. as the
programming language component of the Green Project
at Sun Microsystems ·
launched in 1995 as a “programming language for the
Internet”; quickly gained popularity with the success of the
World Wide Web
JAVA PROGRAMMING
Characteristics
Simple: derived from C/C++, but easier to learn
Secure: built-in support for compile-time and run-
time security
Distributed: built to run over networks
Object-oriented: built with OO features
JAVA PROGRAMMING
Characteristics
Robust: featured memory management,
exception handling, etc.
Portable: “write once, run anywhere''
JAVA PROGRAMMING
JAVA DEVELOPMENT KIT(JDK)
is a software development environment used for
developing Java applications and applets.
- Java Runtime Environment (JRE) - Archiver (jar)
- Java Virtual Machine (JVM) - Compiler (javac)
- Document generator (Javadoc) - Java Development tools
JAVA PROGRAMMING
JAVA DEVELOPMENT KIT(JDK)
Examples of Java API Class Library Packages
java.lang : basic language functionality
java.io : input and output capabilities
java.util : utility classes, collection classes
java.net : network access
java.sql : database access
java.awt, javax.swing : graphical user interfaces
JAVA PROGRAMMING
Process of Programming
JAVA PROGRAMMING
Process of Programming
Create
Compile
Run (or execute)
JAVA PROGRAMMING
JAVA INTEGRATED DEVELOPMENT ENVIRONMENT
(java IDE)
JAVA PROGRAMMING WITH NETBEANS
NETBEANS
- an integrated development
environment for Java
- allows applications to be
developed from a set of modular
software components called
modules
JAVA PROGRAMMING WITH NETBEANS
NEW PROJECT (ctrl + shift + n)
1. Select Project Type 2. Set project name and drive location
JAVA PROGRAMMING WITH NETBEANS
NEW SOURCE FILE (ctrl + n)
1. Select file Type 2. Set file name and project
JAVA PROGRAMMING CONTROL AREA
REFERENCE AREA WORKING AREA
STATUS AREA
JAVA PROGRAMMING
CODING CONVENTION AND DATA TYPES
Java programs are made up of one or more classes.
Byconvention, Java class names start with an
uppercase letter. Java programs are case-sensitive.
A Java source code file usually contains one class
declaration, but two or more classes can be declared in
one source code file. The file is named after the class it
declares, and uses a .java filename extension.
CODING CONVENTION AND DATA TYPES
For a class to be executable, it must be declared public,
and must provide a public static method called main,
with an array argument of type String.
If a file contains more than one class declaration, only
one of the classes can be declared public, and the file
must be named after the sole public class.
CODING CONVENTION AND DATA TYPES
Main rules regarding the usage of semicolon ( ; )
1. Statement Terminator: The semicolon is used to terminate
statements. Each statement in Java must end with a semicolon,
which tells the compiler that the statement is complete.
CODING CONVENTION AND DATA TYPES
Main rules regarding the usage of semicolon ( ; )
2. Multiple Statements: You can write multiple statements on a
single line, separating them with semicolons:
CODING CONVENTION AND DATA TYPES
Main rules regarding the usage of semicolon ( ; )
3. Control Structures: Do not use a semicolon after control
structure declarations like if, for, while, etc., unless it’s part of the
statement body.
CODING CONVENTION AND DATA TYPES
ELEMENTS
Identifiers
Data Types
Main() method
Comments
CODING CONVENTION AND DATA TYPES
IDENTIFIERS
• Are names given to a variable, class, or method
• Can start with a letter, underscore(_), or dollar sign($)
• Are case sensitive and have no maximum length
Examples:
Identifier, username, user_name, _sys_var1 ,$change
CODING CONVENTION AND DATA TYPES
IDENTIFIERS
• Must not used a reserved word
CODING CONVENTION AND DATA TYPES
Class Names - For all class names the
first letter should be in Upper Case.
If several words are used to form a name of
the class, each inner word's first letter should
be in Upper Case.
Example class MyFirstJavaClass
CODING CONVENTION AND DATA TYPES
Method Names - All method names should
start with a Lower Case letter.
If several words are used to form the name
of the method, then each inner word's first
letter should be in Upper Case.
Example public void myMethodName()
CODING CONVENTION AND DATA TYPES
Program File Name - Name of the
program file should exactly match the
class name.
CODING CONVENTION AND DATA TYPES
DATA TYPE
- a set of values and a set of operations defined on them.
Characters (char)
an alphanumeric character or symbol
Strings (String)
a sequence of characters
CODING CONVENTION AND DATA TYPES
Integer (int)
is an integer (whole number) between -231 and 231 - 1
(-2,147,483,648 to 2,147,483,647)
Long (long)
can represent integers in a much larger ranger,
between -263 an 263 - 1.
CODING CONVENTION AND DATA TYPES
Short (short)
has a minimum value of -32,768 and a maximum
value of 32,767 (inclusive)
Byte (Byte)
Ithas a minimum value of -128 and a maximum
value of 127 (inclusive)
CODING CONVENTION AND DATA TYPES
Double (double)
for representing floating-point numbers, e.g., for use
in scientific applications.
Booleans (boolean)
two values: true or false.
CODING CONVENTION AND DATA TYPES
EXCERCISE
Identify what time of data are the following
1. 123 = Byte 6. “False” = String
2. 6744.66 = Double 7. @ = Character
3. 32455 = Short 8. -260 = Long
4. False = Boolean 9. 2,147,483,647 = Integer
5. ‘C’ = Character 10. “Engineer” = String
JAVA OUTPUT AND INPUT
JAVA OUTPUT (println)
JAVA OUTPUT AND INPUT
JAVA OUTPUT (print)
JAVA OUTPUT AND INPUT
JAVA OUTPUT (printf)
The printf command understands a series of characters
known as a format specification.
JAVA OUTPUT
AND INPUT
CODING CONVENTION AND DATA TYPES
CODING CONVENTION AND DATA TYPES
class Example {
public static void main(String args[]) {
System.out.println("First line\nSecond line");
System.out.println("A\tB\tC");
System.out.println("D\tE\tF") ;
}
}
Predicted Output:
First Line
Second Line
A B C
D E F
CODING CONVENTION AND DATA TYPES
EXAMPLE:
CODING CONVENTION AND DATA TYPES
JAVA INPUT (Using Scanner) To use scanner, you have to import it to
your program from JAVA UTILITY
To start using scanner, create
new scanner object
“input” is a variable
Syntax to get the input value
and save it to a variable
(ex. number)
CODING CONVENTION AND DATA TYPES
JAVA INPUT (Using Scanner)
Reading Multiple Inputs on the Same Line
space or next line (return key) as delimiter
CODING CONVENTION AND DATA TYPES
JAVA INPUT (Using JOptionPane)
CODING CONVENTION AND DATA TYPES
MAIN() METHOD
ACCESS SPECIFIER RETURN TYPE STRING ARRAY
public static void main(String[] args)
ACCESS MODIFIER METHOD NAME
• Java program processing starts from the main() method which is a mandatory
part of every Java program
CODING CONVENTION AND DATA TYPES
Comments- must be included in the program.
• /* text */
• /** documentation */
• //
CODING CONVENTION AND DATA TYPES
public class MyFirstJavaProgram {
/* This is my first java program.
* This will print 'Hello World' as the output
*/
public static void main(String []args) {
System.out.println("Hello World"); //prints Hello World
}
}
End of Module 2a
