If a function is inline, the compiler places a copy of the code of that function at each point where the function is called at compile time. One of the important advantages of using an inline function is that it eliminates the function calling overhead of a traditional function.

Abstraction is the process of showing the essential details to the user and hiding the details which we don’t want to show to the user or hiding the details which are irrelevant to a particular user.

No destructor overloading is not possible. Destructors take no arguments, so there’s only one way to destroy an object. That’s the reason destructor overloading is not possible.

In call by value method, we pass a copy of the parameter is passed to the functions. For these copied values a new memory is assigned and changes made to these values do not reflect the variable in the main function.
In call by reference method, we pass the address of the variable and the address is used to access the actual argument used in the function call. So changes made in the parameter alter the passing argument.

A class is called an abstract class whose objects can never be created. Such a class exists as a parent for the derived classes. We can make a class abstract by placing a pure virtual function in the class.

C++ was discovered in order to cope with the disadvantages of C.

Delete is used to release a unit of memory, delete[] is used to release an array.

The Object is the instance of a class. A class provides a blueprint for objects. So you can create an object from a class. The objects of a class are declared with the same sort of declaration that we declare variables of basic types.

new() is a preprocessor while malloc() is a function. There is no need to allocate the memory while using "new" but in malloc() you have to use sizeof(). "new" initializes the new memory to 0 while malloc() gives random value in the newly allotted memory location. The new() operator allocates the memory and calls the constructor for the object initialization and malloc() function allocates the memory but does not call the constructor for the object initialization. The new() operator is faster than the malloc() function as operator is faster than the function.

There are two ways:
• By using the DLL's type library.
• Taking a reference to the function from the DLL instance.

Class is a user-defined data type in C++. It can be created to solve a particular kind of problem. After creation, the user is not required to know the details of the working of a class. In general, class acts as a blueprint of a project and can include in various parameters and functions or actions operating on these parameters. These are called the members of the class.

Using Declaration is used to refer a name from the namespace without the scope resolution operator.

Class is a blueprint of a project or problem to be solved and consists of variables and methods. These are called the members of the class. We cannot access methods or variables of the class on its own unless they are declared static. In order to access the class members and put them to use, we should create an instance of a class which is called an Object. The class has an unlimited lifetime whereas an object has a limited lifespan only.

A conversion constructor is declared with the explicit keyword. The compiler does not use an explicit constructor to implement an implied conversion of types. Its purpose is reserved explicitly for construction.

The static member variable shares a common memory across all the objects created for the respective class. We need not refer to the static member variable using an object. However, it can be accessed using the class name itself.

A static member function can access only the static member variable of the class. Same as the static member variables, a static member function can also be accessed using the class name.

“Register” variable should be used whenever the variable is used. When a variable is declared with a “register” specifier, then the compiler gives CPU register for its storage to speed up the lookup of the variable.

“delete[]” is used to release the memory allocated to an array which was allocated using new[].
“delete” is used to release one chunk of memory which was allocated using new.

Inline function is a function that is compiled by the compiler as the point of calling the function and the code is substituted at that point. This makes compiling faster. This function is defined by prefixing the function prototype with the keyword “inline”.
Such functions are advantageous only when the code of the inline function is small and simple. Although a function is defined as Inline, it is completely compiler dependent to evaluate it as inline or not.

In C++, equal to (==) and assignment operator (=) are two completely different operators. Equal to (==) is an equality relational operator that evaluates two expressions to see if they are equal and returns true if they are equal and false if they are not.
The assignment operator (=) is used to assign a value to a variable. Hence, we can have a complex assignment operation inside the equality relational operator for evaluation.

A mutable storage class specifier is applied only on the class's non-static and non-constant member variable. It is used for altering the constant class object's member by declaring it. This can be done by using a storage class specifier.

No, we cannot have a String Primitive data type in C++. Instead, we can have a class from the Standard Template Library (STL).

Yes, we can use access specifiers to achieve data hiding in C++. These include Private and Protected.

A Block scope variable is the one that is specified as a block using the C++ that can be declared anywhere within the block.

The keyword “Auto” is used by default for various local variables to make function work automatically.

Though both codes will generate the same output, sample code 2 is a more performant option. This is due to the fact that the post-increment ‘itr++’ operator is more expensive than the pre-increment ‘++itr’ operator. The post-increment operator generates a copy of the element before proceeding with incrementing the element and returning the copy. Moreover, most compilers will automatically optimize sample code 1 by converting it implicitly into sample code 2.

Yes, it is possible. However, as the main() function is essential for the execution of the program, the program will stop after compiling and will not execute.

Function overloading allows two or more functions with different type and number of parameters to have the same name. On the other hand, operator overloading allows for redefining the way an operator works for user-defined types.

The ‘this’ pointer is a constant pointer, and it holds the memory address of the current object. It passes as a hidden argument to all the nonstatic member function calls. Also, it is available as a local variable within the body of all the nonstatic functions. As static member functions can be called even without any object, i.e., with the class name, the ‘this’ pointer is not available for them.

Even though it is possible to call an inline function from within itself in C++, the compiler may not generate the inline code. This is so because the compiler won’t determine the depth of the recursion at the compile time. Nonetheless, a compiler with a good optimizer is able to inline recursive calls until some depth is fixed at compile-time and insert non-recursive calls at compile time for the cases when the actual depth exceeds run time.

"Volatile" is a function that helps in declaring that the particular variable is volatile and thereby directs the compiler to change the variable externally- this way, the compiler optimization on the variable reference can be avoided.

Assignment operator in C++ is used to assign a value to another variable. a = 5; This line of code assigns the integer value 5 to variable a. The part at the left of the =operator is known as an lvalue (left value) and the right as rvalue (right value). Lvalue must always be a variable whereas the right side can be a constant, a variable, the result of an operation or any combination of them. The assignment operation always takes place from the right to left and never at the inverse. One property which C++ has over the other programming languages is that the assignment operator can be used as the rvalue (or part of an rvalue) for another assignment.

Abstraction can be defined as a technique in which you only show functionality to the user i.e., the details that you want the user to see, hiding the internal details or implementation details.

STL stands for standard template library. It is a library of container templates that provide generic classes and functions.

You can define a friend function as a function that can access private, public and protect members of the class. You declare the friend function with the help of the friend keyword. You declare this function inside the class.

In the call by value method, you pass the copies of actual parameters to the function's formal parameters. This means if there is any change in the values inside the function, then that change will not affect the actual values. In the call-by-reference method, the reference or address of actual parameters is sent to the function's formal parameters. This means any change in values inside the function will be reflected in the actual values.

You use the void() return type when you don’t want to return any value. It specifies that the function doesn’t return a value. A function with a void return type completes its task and then returns the control to the caller.

Yes, you can compile a program without the main function, but you cannot run or execute the program because the main() function is the entry point, from where all the execution begins. And without the entry point, then you can execute the program.

In prefix (++i), first, it increments the value, and then it assigns the value to the expression.
In postfix (i++), it assigns the value to the expression, and then it increments the variable's value.

A class template is used to create a family of classes and functions. For example, we can create a template of an array class which will enable us to create an array of various types such as int, float, char, etc.
Similarly, we can create a template for a function, suppose we have a function add(), then we can create multiple versions of add().