programming in java
TRANSCRIPT
The most striking feature of the language is that it is PLATFORM-
NEUTRAL language.
Is the FIRST programming language that is not tied to any particular
hardware or OS.
JAVA programs can be executed anywhere on any system.
BUZZWORDS.
JAVA BUZZWORDS (Features)
Compiled & Interpreted Multi-Threaded
Platform-Independent & Portable Object-Oriented
Simple High Performance
Safe (Secure) & Robust Dynamically Linked
Garbage Collected. Distributed
PROGRAMMING IN JAVA
-Ankita Karia
JAVA ENVIRONMENT
DEVELOPMENT TOOLS CLASSES AND METHODS.
are part of the system known as JDK (Java Development Kit).
JAVA ENVIRONMENT
Are part of JSL (Java Standard Library), also known as API (Application Programming Interface)
Collection of tools used for developing and running JAVA programs
JAVA DEVELOPMENT KIT
java –This tool is an interpreter and can interpret the class files generated by the javac compiler
javac – the compiler, which converts source code into Java bytecode
javadoc – the documentation generator, which automatically generates documentation from source code
jdb – the debugger javap – the class file disassembler appletviewer– this tool can be used to run and debug
Java applets without a web browser
EXECUTION STEPS IN JAVA To create a program in JAVA, we need to create a source code file
using a text editor. The source code is then compiled using the JAVA COMPLIER javac And then the program is executed using JAVA interpreter java.
TEXT EDITOR
JAVA SOURCE
CODE
javac
JAVA CLASS FILE
java
JAVA PROGRAM OUTPUT
Compile source code
into bytecode
INTERPRETER
HOW TO WRITE A
JAVA PROGRAM?????
C++ program
void main(){ cout<< “ My first
C++ program”; getch();}
JAVA Program class First { public static void main( String
args[]) { System.out.println(“My first
JAVA program”); }}
Since, JAVA is a true OO Language, Everything must be placed inside a class.
WHERE TO WRITE JAVA PROGRAM
TEXT EDITOR IS USED to write JAVA program
NEXT WHAT?????????? Save your program with file name same as class
name. Extension of the file is java (eg:- first.java)
NEXT WHAT?????????? Compile your program using javac compiler. For that go to DOS prompt;
Go to drive where your java file is stored
NEXT WHAT?????????? STEP 2
NEXT IMPORTANT STEP
Compiling USING javac compiler
EXECUTION OF BYTECODE USING JAVA INTERPRETER
EXPLANATION OF PROGRAM
public Is an ACCESS SPECIFIER that declares main as unprotected & thus is accessible to all classes
static Declares the method as one that belongs to entire class
void Means main does not returns value
args Contains an array of objects of the class type String
println Is a method and it is a member of out object
out Is a static data member of System class.
System Is a class
System.out.println is similar to “cout” of C++
MORE ON BASICS OF JAVAOUTOUT STATEMENTS:
println(name);prints out what is stored in name, then goes to a new line
print(name);prints out what is stored in name, but does not start a new line
print("My name is " + name);put text in quotesuse + to print more than one item.
COMMENTS: JAVA permits both single-line and multi-line comments.
Single-line comments starts with //
Multi-line comments starts with /* and ends with */
MORE ON BASICS OF JAVA Every JAVA statement must end with a semicolon. JAVA is case-sensitive. Thus, Main is different from main in JAVA.
CASCADING IN JAVA + is used to print more than one item.E.g.:-System.out.println(“GOOD MORNING”);System.out.println(“FE6”);System.out.println(“CP II Lecture”);
ORSystem.out.println(“GOOD MORNING”+”\n FE6”+”\t CP II Lecture”);
HOW TO CREATE BYTECODE
javap –c first
FILE NAME