Learn with our youtube video – 7 Minutes

Windows User

1-Installation of java (java development kit)

Step 1:- Download the latest Java software (JDK) from oracle home site

->click this link (http://www.oracle.com/technetwork/java/javase/downloads/index.html)

->Download the “Windows xxx Installer”

Step 2: Set the path – Path is required for using tools i.e. javac, java etc.,

For setting path permanently, perform these steps->

* Go to My computer/This PC ‘properties’ -> ‘advanced system settings’ -> ‘Environment Variables ‘-> ‘New’: it should be like following:

“Variable name: path

“Variable Value: (path of bin folder of JDK) i.e. C:\Program Files\Java\jdkX.X._XX\bin

Congratulations!

Linux User

Step 1- Go to Application -> Accessories -> Terminal.

Step 2-Type command as below..

sudo apt-get install openjdk-8-jdk

Note-change 8 in above line with current java version.

Step 3- For “JAVA_HOME” (Environment Variable) type command as shown below, in “Terminal” using your installation path…

(Note: the default path is as shown, but if you have install OpenJDK at other location then set that path.)

export JAVA_HOME = /usr/lib/jvm/java-8-openjdk

Step 4- For “PATH” (Environment Value) type command as shown below,
in “Terminal” using your installation path…

Note: the default path is as shown, but if you have install OpenJDK at other location then set that path.)

export PATH = $PATH:/usr/lib/jvm/java-X-openjdk/bin

You are done !! Now to check whether installation is done correctly, type java -version in the Terminal.
You will see that java is running on your machine.

Mac Users –   How to Install JDK on macOS

Step 1: Download JDK

1. Goto JDK (or Java SE) download site @ https://www.oracle.com/java/technologies/javase-downloads.html.
2. Under “Oracle JDK”, click “JDK Download”.
3. Download the “macOS DMG installer” (e.g, jdk-15.0.{x}_osx-x64_bin.dmg – about 172MB, where {x} is a fast changing update number).

Step 2: Install JDK/JRE

1. Double-click the downloaded Disk Image (DMG) file. Follow the screen instructions to install JDK/JRE.
2. Eject the DMG file.
3. To verify your installation, open a “Terminal” and issue these commands.

// Display the JDK version

javac -version javac 15.0.{x}

// Display the JRE version

java -version java version “15.0.{x}” .

// Display the location of Java Compiler which javac /usr/bin/javac

// Display the location of Java Runtime which java /usr/bin/java

2-Installation of IDE

There are many ide for development, but here are top in list, install any one-

(1)- Intelij
(2)- Eclipse
(3)- Netbeans

3- FIRST java program – (Shows a text in console(cMD))

Some common rules to follow-

1- Filename should be same as Class name (i.e FirstProg.java)

2- Class name must be start with Uppercase letter (i.e FirstProg (same as filename))

public class FirstProg {
    public static void main(String[] args){
        System.out.println("Yes It's working fine here");
    }
}

public class FirstProg {

‘public’ Java modifier (Step – 8)

‘class’ is keyword (Step – 4)

‘FirstProg’ is user defined custom class name

‘{‘ is open curly bracket for group of code lines

public static void main(String[] args){

‘public’ Java modifier (Step – 8),

‘static’ Java modifier (Step – 8),

‘void’ is keyword which is used when we don’t return anything (String,int etc)

‘main’ is method name (JVM searches for method whose name is ‘main’ and executes it)

( ) after method name shows parameters

(String[] args) – we are passing String[] args as parameter to ‘main’ method,

String – It’s a class which is used as non primitive datatype in java, it’s used to support text data. (String a = ‘any text’)

String[] – [] is symbol used to show array, so String[] is array of Strings
i.e String[] b = [‘any text’, ‘some more’, ‘and more’]

args – It’s just a name declaration for String[] (just like ‘b’ in above example)-(you can use any name instead of args if you want to change)

System.out.println(“Yes It’s working fine here”);

System – System is class in java.lang package(folder)

out – It’s a object of PrintStream class inside System class

println – It’s a method declared in PrintStream class

System.out.println is way to print any text in console in java