The requirement for Java Hello World Example

For executing any java program, you need to

• Install the JDK or BLUEJ if you don't have installed it, download the JDK and install it.

• Create the java program

• Compile and run the java program

Simple java Program

class Simple{

public static void main(String args[]){

System.out.println("Simple Java");

}

}

Explanation of terms used in simple java programs:

• class keyword is used to declare a class in java.

• public keyword is an access modifier which represents visibility. It means it is visible to all.

• static is a keyword. If we declare any method as static, it is known as the static method. The core advantage of the static method is that there is no need to create an object to invoke the static method. The main method is executed by the JVM, so it doesn't require to create an object to invoke the main method. So it saves memory.

• void is the return type of the method. It means it doesn't return any value.

• main represents the starting point of the program.

• String[] args is used for command line argument. We will learn it later.

• System.out.println() is used to print statement. Here, System is a class, out is the object of PrintStream class, println() is the method of PrintStream class. We will learn about the internal working of System.out.println statement later.