What is casting in C++? What is a cast operator? What types of casting can be used in C++? What is dynamic_cast in C++? How can I use dynamic_cast in C++?
C++ is a fast and powerful programming language and excels at all sorts of different operations, such as manipulating data, operations with pointers, operations between classes, etc. In C++, both structs and classes can be used with dynamic_cast operations.
In this post, we will explain how to use dynamic_cast in C++.
What is do we mean by ‘cast’ in C++?
Casting is a technique by which one data type to another data type. The operator used for this purpose is known as the cast operator. It is a unary operator which forces one data type to be converted into another data type. It takes on the format:
In C++, a cast operator is an Unary Operator which forces one data type to be converted into another data type.
In general, C++ supports four types of casting:
- Static Cast
- Dynamic Cast
- Const Cast
- Reinterpret Cast
In C++ what is a Dynamic Cast?
A Dynamic Cast (dynamic_cast) is a safe cast operator that converts pointers or references to classes up, down, and sideways along the inheritance hierarchy. This cast is used for handling polymorphism. We can use dynamic_cast when we cast to a derived class. Thus, it can be used exclusively in inheritance when you cast from base class to derived class.
Is there an example of a Dynamic Cast in C++?
This is a simple example of using dynamic cast where the base is TBase.
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derived = dynamic_cast<TDerived*>( base ); |
Here is the full example of how to perform a Dynamic Cast,
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#include<iostream> #include <exception> class TBase { public: float base_g = 9.81; virtual void dummy() { }; }; class TDerived: public TBase { public: float local_g = 9.78; }; int main() { TBase * base = new TDerived; TDerived * derived; derived = dynamic_cast<TDerived*>( base ); std::cout << derived->base_g << std::endl; std::cout << derived->local_g << std::endl; getchar(); return 0; } |
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