Simple Program of Java ( complete guide to write a java program )
- Mahesh Bhat M
- Jun 23, 2017
- 1 min read
Requirement for Hello Java Example
For executing any java program, you need to
install the JDK if you don't have installed it, download the JDK and install it.
set path of the jdk/bin directory. http://www.javatpoint.com/how-to-set-path-in-java
create the java program
compile and run the java program
Creating hello java example
Let's create the hello java program:
class Simple{
public static void main(String args[]){
System.out.println("Hello Java");
}
}
save this file as Simple.java
To compile:javac Simple.java
To execute:java Simple
Output:Hello Java
Understanding first java program
Let's see what is the meaning of class, public, static, void, main, String[], System.out.println().
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 static method. The core advantage of static method is that there is no need to create object to invoke the static method. The main method is executed by the JVM, so it doesn't require to create 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 startup of the program.
String[] args is used for command line argument. We will learn it later.
System.out.println() is used print statement. We will learn about the internal working of System.out.println statement later.
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