Introduction to Java

Java is an object-oriented programming language developed by Sum Microsystems in1991.

It was originally called oak by James Goslin(one of the inventors of Java.


JAVA = purely object-oriented

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How java works

Java is compiled into bytecode and then it is interpreted into machine code.

source code compiled bytecode interpreted to machine code for given to the machine.

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Java installation

go to google and type "install JDK"  >> install Java JDK

go to google and type "install IntelliJ idea" >>install Java IDE (community version)

 

JDK >> java development kit =collection of tools used in developing and running java programs

JRE  >>java runtime environment =helps in executing programs developed in java

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Basic Structure of a Java Program

package Com.Company; ---> groups classes!

public class Main{

     public static void Main (String [] args){

                System.out.println("Hello World");

                }

     }

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Naming Conventions

>>for classes 

we use the Pascal convention. First and subsequent characters from a word are capital lattes (uppercase)

example: Main, MyScanner, MyEmployee, CodeWithHarry

>>for functions and variables

we use the camelCase Convention. Here the first character is lowercase and the subsequent character is uppercase like below.                                                                                                                                    

 main, myScanner, myMarks,codeWithHarry










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