Virtual function: Virtual function is a member function which is declared within a base class and is redefined by a derived class.
Inline function: Inline function is a normal function which is defined by the keyword inline, it is a short function which is expanded by the compiler and its arguments are evaluated only once.
The syntax of defining the function inline in C++ is:
inline return-type function-name(parameters)
{
// function code
}
Difference between virtual function and inline function are as follows:
Virtual function | Inline function |
| 1. Virtual function must be declared in public section of class. | 1. Inline function is a normal function which is defined by the keyword inline. |
| 2. Virtual function cannot be static. | 2. Inline function can also be non-static. |
| 3. Virtual function is defined in base class. | 3. Inline function are the short length functions that are automatically made the inline functions without using the inline keyword inside the class. |
| 4. Virtual function are used to decrease the efficiency of code. | 4. Inline function are used to increase the efficiency of code. |
| 5. Virtual function is to run time polymorphism. | 5. Inline function is to compile time polymorphism. |
| 6. Virtual function may consists of virtual destructor but it cannot have a virtual constructor. | 6. Inline function can also consist of inline constructor. |
| 7. Virtual may use for dynamic linkage. | 7. Inline function is used to reduce the function call overhead. |