Why do we use #include in C?

The #include preprocessor directive is used to paste code of given file into current file. If included file is not found, compiler renders error. By the use of #include directive, we provide information to the preprocessor where to look for the header files.

Do all C programs need a main?

All C language programs must have a main() function. It’s the core of every program. It’s required. The main() function doesn’t really have to do anything other than be present inside your C source code.

Can a program run without main () in C?

We can write c program without using main() function. To do so, we need to use #define preprocessor directive. The C preprocessor is a micro processor that is used by compiler to transform your code before compilation. It is called micro preprocessor because it allows us to add macros.

Can a program run without main in C?

directive #define with arguments to give an impression that the program runs without main. But in reality it runs with a hidden main function. The ‘##’ operator is called the token pasting or token merging operator. So actually C program can never run without a main() .

Can a program run without main?

Yes, we can execute a java program without a main method by using a static block. Static block in Java is a group of statements that gets executed only once when the class is loaded into the memory by Java ClassLoader, It is also known as a static initialization block.

What will happen if we call main method in Static Block?

Example. We observe that JVM first executes the static block, if it is present in the program. After that it searches for the main() method. If the main() method is not found, it gives error.

Can we override main method?

Short answer is NO, we can not override main method in java. Reason is very simple. As main method is static and we know very well that we can not override static methods in Java, hence main method could not be overridden. So what will happen if we will try to override main method in subclass.

Can main method be overloaded?

Yes, we can overload the main method in Java, but When we execute the class JVM starts execution with public static void main(String[] args) method.

Why can we not override static method?

Overloading is the mechanism of binding the method call with the method body dynamically based on the parameters passed to the method call. Static methods are bonded at compile time using static binding. Therefore, we cannot override static methods in Java.

Can Final methods be overloaded?

private and final methods can be overloaded but they cannot be overridden. It means a class can have more than one private/final methods of same name but a child class cannot override the private/final methods of their base class.

Are private methods final?

So, to answer question 2, yes, all compilers will treat private methods as final . The compiler will not allow any private method to be overridden. Likewise, all compilers will prevent subclasses from overriding final methods.

Can we override private method in Java?

No, we cannot override private or static methods in Java. Private methods in Java are not visible to any other class which limits their scope to the class in which they are declared.

What happens if we override private method?

Since method overriding works on dynamic binding, its not possible to override private method in Java. private methods are not even visible to Child class, they are only visible and accessible in the class on which they are declared. private keyword provides highest level of Encapsulation in Java.

Can we declare constructor as private?

Yes, we can declare a constructor as private. If we declare a constructor as private we are not able to create an object of a class. We can use this private constructor in the Singleton Design Pattern.

Is it possible to override protected method to private?

Yes, the protected method of a superclass can be overridden by a subclass. If the superclass method is protected, the subclass overridden method can have protected or public (but not default or private) which means the subclass overridden method can not have a weaker access specifier.