What are the ways to call functions in c++

C There are five ways to call functions: value passing, reference passing, pointer passing, return value, and virtual function calling. Passing by value passes a copy and will not affect the actual parameters; passing by reference passes by reference and modifying the parameters will affect the actual parameters; passing by pointer passes the address and modifying the parameters will affect the actual parameters; the return value function returns to the calling function; virtual function calls are specific to object-oriented Programming, the actual function performed depends on the type of object.

How to call functions in C

In C, there are the following ways to call functions:

1. Value passing (passing a copy)

In value passing, the parameters of the function receive a copy of the actual parameters. When a function modifies a parameter, it does not affect the value of the actual parameter.

2. Pass by reference (pass by reference)

In pass by reference, the parameters of the function refer to the actual parameters. When a function modifies a parameter, the value of the actual parameter is also affected.

3. Pointer passing

In pointer passing, the function parameters point to the memory address of the actual parameters. When a function modifies a parameter, the value of the actual parameter is also affected.

4. Return value

A function can return a value to the function that called it. The return value can be a primitive data type, reference, or pointer.

5. Virtual function call

Virtual function call is a calling method specific to object-oriented programming (OOP). When a virtual function is called, the actual function executed depends on the actual type of the object.

Characteristics of each calling method:

• Value transfer: Safe, will not affect the value of the actual parameter, but will generate additional memory overhead.
• Passing by reference: Efficient and does not incur additional memory overhead, but may cause errors because the function can modify the actual parameters.
• Pointer passing: Flexible, you can pass by value or by reference, but you need to manage pointers carefully.
• Return value: Commonly used, the result is passed back to the calling function by returning a value.
• Virtual function call: Used for OOP to achieve polymorphism.

The above is the detailed content of What are the ways to call functions in c++. For more information, please follow other related articles on the PHP Chinese website!