Understanding Source Code Example in Java

The source code example in Java is where you can find all the files related to your project. When you create a new project in your IDE, locate the Package Explorer panel, which is generally located to the left.

After successfully setting up the environment, we can open a terminal in both Windows and Unix and go to the directory where the file `HelloWorld.java` is present. This is an essential step in understanding how to write and run a Java program.

Every Java program must have a class definition that matches the filename (class name and file name should be same). By convention, the name of the main class (a class that contains the main method) should match the name of the file that holds the program. In Java, all codes must reside inside a class, and there is at most one public class which contains the main() method.

The name of the class defined by the program is `HelloWorld`, which is the same as the name of the file (`HelloWorld.java`). This type of comment must begin with `/*` and end with `*/`. For multiline comments, they can either be multiline or single-line comments. The System is a predefined class that provides access to the system, and `out` is the variable of type output stream connected to the console.

Output is accomplished by the built-in `println()` method. This line outputs the string “Hello, World” followed by a new line on the screen. Notice that it occurs inside the main() method. Like in C/ C++, the main method is the entry point for your application and will subsequently invoke all the other methods required by your program.

The main method accepts a single argument, i.e., an array of elements of type String. The compiler executes the codes starting always from the main function. The main method must be inside the class definition. The modifiers public and static can be written in either order.

The `static` keyword is used to indicate that the main method can be called without creating an instance of the class. The `public` keyword is used to indicate that the main method can be accessed from anywhere.

The signature of the main method in Java is: `public static void main(String args'')`. The main function (method) is the entry point of your Java application, and it's mandatory in a Java program. In the Java programming language, every application must contain a main method.

Source code example java