Learn with our youtube video – 7 Minutes

💻 Windows User

1-Installation of java (java development kit)

    Step 1:- Download the latest Java development kit (JDK) from oracle home site                        A->Oracle Homepage (Click here)
    B->Download the “Windows xxx Installer”

 Step 2: Set the path (of tools) –
      A- Path is required for using tools i.e. javac, java etc.,
      B- For setting path permanently, perform these steps->
      C- * 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!

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.

💻 Linux User

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

sudo apt-get install openjdk-8-jdk

Or

   Step 1:- Download the latest Java development kit (JDK) from oracle home site                                 A->http://www.oracle.com/technetwork/java/javase/downloads/index.html
           B-> Switch tab to Linux

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

Step 2-
   A- Open terminal ->

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

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

Step 3-
 A- Open terminal ->

export PATH = $PATH:/usr/lib/jvm/java-8-openjdk/bin

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

Congratulations!

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 –

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.

Interview Questions —

• What java component(JVM/JRE/JDK) to install for java development?
• Why to set path of bin folder in environment variables?