First, let’s address two questions
◆ What are the differences between pointers and references?
◆ When should we use pointers? When should we use references?
Differences between Pointers and References
See the code below:
A pointer is used to represent a memory address, and this pointer is the address of the variable it points to.
A reference is simply another name for a variable; it is also known as an “alias”.
Differences
◆ A pointer can be declared without initialization, but it must be checked each time it is used to prevent null pointer exceptions. A reference can never be null; it must always refer to an object.
◆ A pointer stores an address and can be reassigned. A reference always points to the original object it represents.
Usage Scenarios for Pointers and References
References are mainly used as function parameters and return values, as shown in the code below:
By using vec[3] = 3, we can change the value of the vector container. This is because the [] operator returns a reference. It gives an alias to the internal variable and allows the [] operator to return a pointer, i.e., *vec[3] = 3. In fact, anything that can be done with references can also be done with pointers. So why use references?
Conclusion
Use the right tool for the right job.
Pointers can operate on anything in memory without constraints, making them very powerful but also dangerous. Therefore, references should be used at appropriate times.
When you need to point to something and ensure it never points to anything else, for example, some function parameters can use references to avoid copying, or to implement an operator whose syntax cannot be achieved with pointers, such as vec[3] = 3, references can be used. In all other cases, pointers should be used.