Answer to Question #168631 in Java | JSP | JSF for Lucy

Question

Why is method main declared static

Answer 1

Java's main() method is always static, so that compiler can call it without the creation of an object or before the creation of an object of the class.

• In any Java program, the main() method is the starting point from where the compiler starts program execution. So, the compiler needs to call the main() method.
• If the main() is allowed to be non-static, then while calling the main() method JVM has to instantiate its class.
• While instantiating it has to call the constructor of that class, there will be ambiguity if the constructor of that class takes an argument.
• The static method of a class can be called by using the class name only without creating an object of a class.
• The main() method in Java must be declared public, static, and void. If any of these are missing, the Java program will compile but a runtime error will be thrown.

Example

class Book {
   public static void getBookInfo() { //static method
      System.out.println("Welcome to TutorialsPoint Library");
   }
}
public class Test {
   public static void main(String[] args) {
      //Call static method of Book class using class name only
      Book.getBookInfo();
   }
}

Output

Welcome to TutorialsPoint Library