C++ Interview Questions Intermediate

C++ Interview Questions – Intermediate Level

Which operations are permitted on pointers?

Pointers are the variables that are used to store the address location of another variable. Operations that are permitted to a pointer are:

Increment/Decrement of a Pointer
Addition and Subtraction of integer to a pointer
Comparison of pointers of the same type

What is the purpose of the “delete” operator?

The delete operator is used to delete/remove all the characteristics/properties from an object by deallocating its memory; furthermore, it returns true or false in the end. In simple terms, it destroys or deallocates array and non-array(pointer) objects which are created by new expressions.

    
            int GFG = new int[100];
            // uses GFG for deletion
            delete[] GFG;

How delete [] is different from delete?

delete[]

It is used for deleting a whole array
It is used for deleting the objects of new[]; By this, we can say that delete[] is used to delete an array of objects
It can call as many destructors it wants

delete

It is used to delete only one single pointer
It is used for deleting the objects of new; By this, we can say that delete is used to delete a single object
It can only call the destructor of a class once

What do you know about friend class and friend function?

A friend class is a class that can access both the protected and private variables of the classes where it is declared as a friend.
Example of friend class:

    
                class Class_1st {
                // ClassB is a friend class of ClassA
                friend class Class_2nd;
                statements;
                } class Class_2nd {
                 statements;
                }

A friend function is a function used to access the private, protected, and public data members or member functions of other classes. It is declared with a friend keyword. The advantage of a friend function is that it is not bound to the scope of the class and once it is declared in a class, furthermore to that, it cannot be called by an object of the class; therefore it can be called by other functions. Considering all the mentioned points we can say that a friend function is a global function.
Example of friend function:

    
            class GFG {
             statements;
            friend dataype function_Name(arguments);
             statements;
            } OR class GFG {
            statements' friend int divide(10, 5);
            statements;
            }

What is an Overflow Error?

Overflow Error occurs when the number is too large for the data type to handle. In simple terms, it is a type of error that is valid for the defined but exceeds used the defined range where it should coincide/lie.
For example, the range of int data type is –2,147,483,648 to 2,147,483,647 and if we declare a variable of size 2,247,483,648 it will generate a overflow error.

C++ Interview Questions Intermediate