Introduction
Java’s main() method is the entry point to start program execution. There are at least one class and one main method in every Java program.
Typically, an application consists of many classes, and only one of these classes must have a main method.
In this blog, we will discuss Java’s main method.
Java Main() Method
Simply put, a complex program can contain dozens of classes, but only one of them must have a main() method in order for the program to run. As a result, your program’s main() function in Java serves as its entry point.
or,
Main() is the starting point for the JVM to execute a Java program. Without the main() method, the JVM will not start the program. The syntax of the main() method is:
Syntax:
public static void main(String[] args)
{
// This is where the method body goes.
}
public: This is an access specifier. We should use the public keyword before the main() method so that the JVM can identify the point of program execution. If we use private, protected, and default before the main() method, it will not be visible to the JVM.
static: You can make a method static using the static keyword. We should call the main() method without creating the object. Static methods are called without creating objects, so we don’t need any object to call the main() method.
void: In Java, every method has a return type. The Void keyword confirms to the compiler that the main() method does not return any value.
main(): It is the default signature that is predefined in the JVM. It is called by the JVM to execute the program line by line and terminate execution when this method completes. We can also overload the main() method.
String args[]: Additionally, the user can provide some data to the main() method. It will accept an array of strings, which is a collection of strings. Used to store command line arguments as string values.
main(String args[]): Here, agrs[] is the field name and is of type String. This means it can store a group of strings. Note that this array can also store a group of numbers, but only in string form. The values passed to the main() method are called arguments. These arguments are stored in the args[] array, so the name args[] is generally used.
Why is Public Static Void Main in Java?
An application program written in Java is launched from the public static void main(String [] args) function. For this reason, the Java Program’s public static void main method is used or written.
Why Do We Need To Declare The Main Method As Static in Java?
The primary technique is listed as static. When the class is run, the JVM calls it. The JVM is unable to produce an object belonging to the class. It requires a common method to launch program execution.
Therefore, the main method is declared static, so the JVM can call it using the class name passed on the command line.
Why Is The Main Method Declared As Static in Java?
If we don’t declare the main method static, it will be treated as an instance method. The code will compile successfully without generating any error message. But at runtime, the code throws an exception named: “NoSuchmethodError: main”.
Main functions of JavaScript
Java and JavaScript are often confused and serve very different purposes. JavaScript is embedded in the web page. Any code placed inside an HTML script tag on a web page will be executed. There is no need to code core JavaScript functionality when developing a website.
It’s also important to note that Java programmers rarely use the word “function.” The most frequent terminology used to describe the starting point of a Java application is “main method.”
Our Learners Also Read: An Introduction to the Java Programming Language for Beginners
What Is The Main Method in Java?
The main method in Java is the standard method used by the JVM to run any Java program. The main method is referred to as the entry point of a Java application, which is true for core Java applications, but not for container-managed environments such as Servlets, EJBs, or MIDlets, as these Java programs have their own lifecycle methods, such as init (), service() or destroy() for the Servlet that uses the container. The main method in Java is started by the main thread, which is not a daemon thread, and the Java program runs until the main method ends or another user thread is running.
When we start the JVM by running the java command, we also provide the name of the class that contains the main method, later called by the JVM to start executing the Java program.
Can We Run a Java Program Without The Main Method?
Yes, we can run a java program without the main method using static block.
A static block in Java is a group of statements executed only once when a class is loaded into memory using a ClassLoader. It is also a static initialization block that goes into the stack memory.
Difference Between The Main Method in C, C++, and Java
Suppose you come from C and C++ programming languages. In that case, you know the main method because both of these programs also use main() as the entry point to execute the program, but the main method in C and C++ is completely different from the main method in Java.
The main method in Java does not return anything and has a void return type, while the main method in C and ++ returns an int.
That’s all about what is the main method in java, What are valid main method signatures in java, What happens when you put the wrong main method signature, Why the main method is public, static, and void in java, and finally, we saw the difference between the main methods of C, C++, and Java.
Every Java programmer should be aware of this because it is one of the most crucial Java Programming Language principles.
Conclusion
The main method or function serves as the entry point for a standalone Java application. This article demonstrates Java’s main function and explains why it is a public static void in Java.
