Why is public static void main(String[] args) necessary in java?

The public static void main(String[] args) method in Java is used as the entry point for running a Java program. When a Java program is executed, the Java Virtual Machine (JVM) looks for the main method in the specified class and executes it.

The public access modifier allows the main method to be accessed from outside of the class. The static keyword allows the method to be called without creating an instance of the class, which is necessary because the JVM needs to call the method to start the program. The void return type means that the main method does not return any value.

The String[] args parameter allows the main method to accept command line arguments as an array of strings. These arguments can be passed to the program when it is executed, allowing the program to be customized at runtime.

Here is an example of a simple Java program that uses the main method:

In this example, the HelloWorld class contains a public static void main(String[] args) method that prints the message "Hello, world!" to the console when the program is executed. The args parameter is not used in this example, but it could be used to pass arguments to the program if needed. When this program is compiled and executed, the JVM will look for the main method in the HelloWorld class and execute it, resulting in the message "Hello, world!" being printed to the console.