Скачать или смотреть How to Call a Function from a Function Pointer in C+ +

Learn how to effectively call a function from a function pointer in C+ + , including sample code and explanations to help you understand this essential concept.
---
This video is based on the question https://stackoverflow.com/q/73394062/ asked by the user 'anom' ( https://stackoverflow.com/u/15870575/ ) and on the answer https://stackoverflow.com/a/73394128/ provided by the user 'R.J. Dunnill' ( https://stackoverflow.com/u/7970461/ ) at 'Stack Overflow' website. Thanks to these great users and Stackexchange community for their contributions.

Visit these links for original content and any more details, such as alternate solutions, latest updates/developments on topic, comments, revision history etc. For example, the original title of the Question was: How to call a function from a function pointer?

Also, Content (except music) licensed under CC BY-SA https://meta.stackexchange.com/help/l...
The original Question post is licensed under the 'CC BY-SA 4.0' ( https://creativecommons.org/licenses/... ) license, and the original Answer post is licensed under the 'CC BY-SA 4.0' ( https://creativecommons.org/licenses/... ) license.

If anything seems off to you, please feel free to write me at vlogize [AT] gmail [DOT] com.
---
Calling a Function from a Function Pointer in C+ +

In the world of C+ + , function pointers can be a bit perplexing for both newcomers and seasoned developers. You may find yourself needing to call a function using just a pointer to that function. While it sounds straightforward, improper syntax can lead to frustrating errors. In this guide, we will discuss how to properly call a function from a function pointer by breaking down a sample code. You will not only learn how it works, but also why it functions that way.

The Problem: Function Pointer Syntax

Consider the following example where we declare a simple function and attempt to call it through a function pointer:

[[See Video to Reveal this Text or Code Snippet]]

This code aims to print "Hello World!" to the console, but it fails because of the incorrect function pointer syntax used in the run_func definition. Let's explore how to fix this.

The Solution: Correcting Function Pointer Syntax

The key to resolving this issue lies in understanding how to define function pointers correctly. Here’s how we can correct the function pointer syntax to successfully call a function:

Step 1: Use Typedef for Clarity

Instead of directly dealing with function pointer syntax, we can create a typedef that makes our code more readable:

[[See Video to Reveal this Text or Code Snippet]]

Step 2: Redefine the Function Parameter

Next, we will redefine the run_func parameter to accept a function pointer using our new typedef. The revised version of the function looks like this:

[[See Video to Reveal this Text or Code Snippet]]

Final Code Example

Here’s the complete and corrected program:

[[See Video to Reveal this Text or Code Snippet]]

This updated code will now output:

[[See Video to Reveal this Text or Code Snippet]]

Summary of Key Points

Function Pointer: A variable that stores the address of a function, allowing us to call it indirectly.

Using typedef: Simplifies the declaration of function pointers, making code easier to read and understand.

Correct Syntax: When defining functions that take function pointers, ensure proper parentheses are used around the function pointer type.

Conclusion

Understanding how to call functions through pointers in C+ + is a crucial skill for any programmer. By following the simple steps outlined in this post, you can confidently interpret and utilize function pointers in your code, avoiding common pitfalls. Remember, clarity in syntax is just as important as the logic behind your code. Keep practicing, and you'll become adept at mastering function pointers in no time!