This is the question I faced in my interview.
Why is main method in Java called as public static void main(String[] args) ?
Answer:
1.main() must be declared public because it is invoked by JVM whenever the program execution starts.JVM doesnot belong to our program package.
Inorder to access main outside the package we have to declare it as public.If we declare it as anything other than public it shows a Runtime Error but not Compilation time error
2.main() must be declared as static because if a method is declared as static then we can call that method outside the class using ClassName.methodName();
class Sample
{
static void fun()
{
System.out.println("Hello");
}
}
class Test
{
public static void main(String[] args)
{
Sample.fun();
}
}
The JVM will first Load the Test class,and will check for the Commandline arguments and calls the main method as Test.main();
3.main() must be declared as void main() because JVM is not expecting any value from main().So,it must be declared as void.
If other return type is provided,the it is a RunTimeError i.e;NoSuchMethodFoundError.
4.main() must have String arguements as arrays because JVM calls main method by passing command line arguement.As they are stored in string array object it is passed as an argument to main().
