main method in java
The ‘main()’ method in Java serves as the entry point for any Java application. When you run a Java program, the Java Virtual Machine (JVM) starts executing the program by invoking the ‘main()’ method of the class specified as the starting point. Here’s a detailed explanation of the ‘main()’ method:

Table of Contents
1. Signature: The ‘main()’ method has a specific signature:
public static void main(String[] args)
- ‘public’: Indicates that the method is accessible from outside the class.
- ‘static’: Indicates that the method belongs to the class itself, rather than to instances of the class.
- ‘void’: Specifies that the method does not return any value.
- ‘main’: The method name, which is fixed and recognized by the JVM as the entry point of the program.
- ‘String[] args’: The parameter of the ‘main()’ method, which is an array of strings representing command-line arguments passed to the program.
2. Execution:
When you run a Java program, the JVM looks for the ‘main()’ method with the specified signature in the class specified as the entry point.
- If the ‘main()’ method is not found or has a different signature, the JVM throws a NoSuchMethodError.
- If the ‘main()’ method is found, the JVM invokes it to start the program’s execution.
3. Command-Line Arguments:
The args parameter allows you to pass command-line arguments to the Java program when executing it from the terminal.
- Command-line arguments are passed as strings separated by spaces.
- Inside the ‘main()’ method, you can access and process these arguments stored in the args array.
4. Execution Flow:
The statements within the ‘main()’ method define the initial behavior of the Java program.
- You can include code to initialize variables, call other methods, perform computations, interact with users, and more.
- The execution of the ‘main()’ method continues until the end of the method body or until a return statement is encountered.
public class HelloWorld {
public static void main(String[] args) {
// Display "Hello, World!" to the console
System.out.println("Hello, World!");
}
}
- In this example, the ‘main()’ method of the HelloWorld class prints “Hello, World!” to the console when the program is executed.
The ‘main()’ method serves as the starting point for Java programs, providing a standardized entry point for the JVM to initiate program execution. It allows developers to define the initial behavior and logic of their Java applications.