Valid variants of main() in Java

Below are different variants of main() that are valid.

Default prototype: Below is the most common way to write main() in Java.

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

Output:

Main Method

Meaning of the main Syntax:

public:  JVM can execute the method from anywhere.
static:  Main method can be called without object.
void:    The main method doesn't return anything.
main():  Name configured in the JVM.
String[]: Accepts the command line arguments.

Order of Modifiers: We can swap positions of static and public in main().

class Test

{

    static public void main(String[] args)

    {

        System.out.println("Main Method");

    }

}

Output:
```
Main Method
```
Variants of String array arguments: We can place square brackets at different positions and we can use varargs (…) for string parameter.

class Test

{

    public static void main(String[] args)

    {

        System.out.println("Main Method");

    }

}

Output:
```
Main Method
```
class Test

{

    public static void main(String []args)

    {

        System.out.println("Main Method");

    }

}

Output:
```
Main Method
```
class Test

{

    public static void main(String args[])

    {

        System.out.println("Main Method");

    }

}

Output:
```
Main Method
```
class Test

{

    public static void main(String...args)

    {

        System.out.println("Main Method");

    }

}

Output:
```
Main Method
```
Final Modifier String argument: We can make String args[] as final.

class Test

{

    public static void main(final String[] args)

    {

        System.out.println("Main Method");

    }

}

Output:
```
Main Method
```
Final Modifier to static main method: We can make main() as final.

class Test

{

    public final static void main(String[] args)

    {

        System.out.println("Main Method");

    }

}

Output:
```
Main Method
```
synchronized keyword to static main method: We can make main() synchronized.

class Test

{

    public synchronized static void main(String[] args)

    {

        System.out.println("Main Method");

    }

}

Output:
```
Main Method
```
strictfp keyword to static main method: strictfp can be used to restrict floating point calculations.

class Test

{

    public strictfp static void main(String[] args)

    {

        System.out.println("Main Method");

    }

}

Output:
```
Main Method
```
Combinations of all above keyword to static main method:

class Test

{

    final static synchronized strictfp static void main(String[] args)

    {

        System.out.println("Main Method");

    }

}

Output:
```
Main Method
```

Overloading Main method: We can overload main() with different types of parameters.

class Test 
{ 
    public static void main(String[] args) 
    { 
        System.out.println("Main Method String Array"); 
    } 
    public static void main(int[] args) 
    { 
        System.out.println("Main Method int Array"); 
    } 
}

Output:

Main Method String Array

Inheritance of Main method: JVM Executes the main() without any errors.

class A

{

    public static void main(String[] args)

    {

        System.out.println("Main Method Parent");

    }

}



class B extends A

{



}

Two class files, A.class and B.class are generated by compiler. When we execute any of the two .class, JVM executes with no error.
```
O/P: Java A
Main Method Parent
O/P: Java B
Main Method Parent
```

Method Hiding of main(), but not Overriding: Since main() is static, derived class main() hides the base class main. (See Shadowing of static functions for details.)

class A 
{ 
    public static void main(String[] args) 
    { 
        System.out.println("Main Method Parent"); 
    } 
} 
class B extends A 
{ 
    public static void main(String[] args) 
    { 
        System.out.println("Main Method Child"); 
    } 
} 

Two classes, A.class and B.class are generated by Java Compiler javac. When we execute both the .class, JVM executes with no error.

O/P: Java A
Main Method Parent
O/P: Java B
Main Method Child

This article is contributed by Mahesh. Please write comments if you find anything incorrect, or you want to share more information about the topic discussed above

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