Main Method In Java: When we start learning about Java programming, the Java main method is the first thing we need to learn about. After successfully writing the Java program, when we start running our program, Java’s main method is the starting point from where the execution is started.
Inside the main method, we can write our Java code for execution or the invocation of other methods, and you can write the main method inside any class that is part of your program; it can reside within any class that constitutes a part of the program.
In more complex Java programs or real-time application development, we have seen that a dedicated class is created for the main method. We can give any name to that class, but for clarity purposes, the name of the class is “Main”.
How To Write Main Method In Java?
To write the main method, you can follow the below syntax:
public static void main(String[] args)
{
// Method Body
}
After seeing the syntax of the main method, the next thing that may come to your mind is, what is the meaning of writing the main method like this? So, let’s break down the syntax:
public: An access modifier makes the main method accessible from anywhere. In the future, we will discuss access modifiers; you can follow this access modifier link to learn more about them.
static: This keyword indicates that the main method belongs to the class itself, not any specific class instance. It allows the method to be called without creating an object of the class. Learn more at Static Keyword In Java.
void: The main method doesn’t return any value. This means it doesn’t produce a result that needs to be captured or returned.
main: This is the name of the method. In Java, it’s the conventionally accepted name for the method that serves as the entry point for your program.
(String[] args): These are the parameters that the main method accepts. It’s an array of strings (an array of String objects) named args. This parameter allows you to accept command-line arguments when running your Java program. You can access these arguments within the main method to process external input.
When you create a Java application, you must include this main method with this specific syntax so that the Java Virtual Machine (JVM) knows where to start executing your code when you run the program.
But still, there are somany other related questions that come to your mind, such as:
- Why do we write the main method like public static void main in Java?
- Why the main method in Java is static?
- What do you call the main method in Java?
- Can there be more than one main method in the Java class?
- Can we execute without the main method in Java?
- Can we overload the main method in Java?
Let us try to understand each of these questions and find a solution.
Why do we write the main method like public static void main in Java?
We write the main method in Java as a public static void main for the following reasons.
- Accessibility (public): The public keyword ensures that the main method can be accessed from anywhere in the program, including from outside the class where it’s defined. This is essential because the Java Virtual Machine (JVM) needs to locate and execute the main method when launching the program.
- Static Nature (static): The static keyword indicates that the main method belongs to the class, not to class instances. Since the main method needs to be executed before any objects are created, it should be accessible at the class level without needing an instance.
- Return Type (void): The void return type signifies that the main method does not return any value. Instead, it serves as an entry point for the program’s execution, transferring control to other parts of the code.
Overall, this specific signature for the main method in Java ensures that it can be located, accessed, and executed by the JVM as the starting point for running Java applications.
Why the main method in Java is static?
The main method in Java is declared static because this is the entry point of a Java program. This static declaration ensures that the method belongs to the class rather than an instance of the class.
Since the main method is called by the Java Virtual Machine (JVM), before any objects are created, they must be accessible without requiring an instance. It can be invoked directly on the class by making it static, simplifying the startup process, and enabling the JVM to execute the program without needing object instantiation.
How do you call the main method in Java?
We don’t need to call the main method explicitly in Java programming. The Java Virtual Machine (JVM) automatically calls the main method when you run a Java program. Because the main method serves as the entry point for the program, the JVM knows to start execution from there.
If you try to run your Java program in the command prompt, you initiate the program by invoking the Java command followed by the name of the class containing the main method, and the JVM takes care of calling and executing the main method. For example, to run a class named MyProgram with a main method, you’d use the command java MyProgram.
Can there be more than one main method in the Java class?
In a single Java class, we can have more than one main method, but only one can be your program’s actual entry point. The JVM determines the entry point, which looks for the specific signature public static void main(String[] args) when starting the program.
Other main methods with different parameter lists or access modifiers can exist in the same class for various purposes but won’t be used as entry points.
Can we execute without the main method in Java?
No, we cannot execute a program without a main method in Java. The main method serves as the entry point for Java applications. When you run a Java program, the Java Virtual Machine (JVM) looks for the public static void main(String[] args) method and starts executing code from there.
Without a main method, the JVM won’t know where to begin the program’s execution and won’t run. Therefore, the main method is essential for properly executing Java applications.
Can we overload the main method in Java?
Yes, we can overload the main method in Java. Method overloading allows you to define multiple methods in the same class with the same name but different parameter lists. However, only the standard public static void main(String[] args) method will serve as the entry point for your program when you run it.
Overloaded main methods with different parameter types or numbers won’t be recognized as entry points by the Java Virtual Machine (JVM). These overloaded main methods can be used for different purposes within your class, but the JVM will only execute the standard main method with the specified signature.
Conclusion:
In this main method in Java blog post, we have explored the significance of the main method in Java, understanding its critical role as it’s the entry point for executing Java programs. We’ve also reviewed the syntax and why it’s written as the public static void main(String[] args), highlighting its accessibility, static nature, and void return type.
Your understanding of the main method is essential for effective Java programming. If you have any doubts or questions about this topic, please don’t hesitate to comment below. We value your input, so if you have any suggestions to enhance this article or if there are specific Java topics you’d like us to cover in the future, feel free to share your thoughts in the comment section. Your feedback is greatly appreciated!
