Java – hello world

Here we will write Hello World in java and try to understand basics of how it works.

public class HelloWorld{
    public static void main(String[] args){
         System.out.println("Hello World");
    }

}

• How to run?
  • Save the above code in a file with name – HelloWorld.java
  • if you are using an IDE like Eclipse/Intellij , right click on file and click run
  • or from command line
    • first run javac HelloWorld.java
    • then run java HelloWorld
• Now Let’s understand
  • First of all we have described a class here with Name HelloWorld public class HelloWorld
  • In this we described a function with name main as public static void main
  • Main function with this signature is special to java as it calls this main function when your program runs.
  • Now in this main function we have written System.out.println("Hello World");
  • With this line we are telling the System to print the text passed(which is “Hello World” in this case) and system prints this on the command line.

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