Java main() Method Interview Questions with Answers

FAQ Section

1. Why is the main() method public static void in Java?
2. Can we overload the main() method in Java?
3. Can the main() method be declared private, protected, or without any modifier?
4. Is it possible to declare the main() method as non-static?
5. Can we change the return type of the main() method?
6. Can the main() method accept arguments other than String[]?
7. Can a Java program run without the main() method?
8. Can the main() method be declared final in Java?

1. Why is the main() method public static?

• Public → JVM needs to access it from outside the class.
• Static → JVM can call it without creating an object of the class.

public class Test {
    public static void main(String[] args) {
        System.out.println("Program starts here!");
    }
}

👉 If main() were not public, JVM would not be able to access it.
👉 If it were not static, JVM would need to instantiate the class before calling it, which may not be possible.

2. Can we overload the main() method in Java?

✅ Yes, you can overload main() with different parameter lists, but JVM always calls the standard one:

public class Test {
    public static void main(String[] args) {
        System.out.println("Main with String[] called");
        main(10);  // You can call overloaded versions manually
    }

    public static void main(int x) {
        System.out.println("Overloaded main with int: " + x);
    }
}

Output :

Main with String[] called
Overloaded main with int: 10

3. Can we declare the main() method as private, protected, or with no access modifier?

❌ No. JVM requires main() to be public. If you try other access modifiers, you get a runtime error:

class Test {
    private static void main(String[] args) {
        System.out.println("Won’t run!");
    }
}

Output:

Error: Main method not found in class Test

4. Can we declare the main() method as non-static?

❌ No. If main() is not static, JVM cannot call it without creating an object.

class Test {
    public void main(String[] args) { // non-static
        System.out.println("This won't run!");
    }
}

Output:

Error: Main method is not static in class Test

5. Can we change the return type of the main() method?

❌ No, it must be void.
If you try to return something, JVM won’t recognize it as the entry point.

class Test {
    public static int main(String[] args) {
        return 0; // Invalid main()
    }
}

Output:

Error: Main method must return a value of type void

6. Can the main() method take an argument other than String[]?

❌ No. JVM recognizes only String[] (or String... args using varargs).
Other parameter types won’t work.

class Test {
    public static void main(int[] args) { // Invalid signature
        System.out.println("Won’t run!");
    }
}

Valid alternative:

public static void main(String... args) {
    System.out.println("Valid with varargs");
}

7. Can we run a Java class without the main() method?

• In Java 7 and earlier, you could use a static block as an entry point.
• From Java 8 onward, it is mandatory to have main(); otherwise, JVM throws an error.

class Test {
    static {
        System.out.println("Static block executes");
        System.exit(0); // Exit without main()
    }
}

✅ Works in Java 6/7
❌ Throws error in Java 8+

8. Can we make the main() method final in Java?

✅ Yes, you can declare main() as final. It still runs normally because JVM only calls it, not overrides it.

class Test {
    public final static void main(String[] args) {
        System.out.println("Main declared as final");
    }
}

Output:

Main declared as final

📌 Summary Table