Скачать или смотреть How to Handle User Input for Integers in C Programming Using Loops

Learn how to create a user-friendly C program that continuously prompts for integer input until valid data is received. Improve error handling and enhance user interaction in your C programs!
---
This video is based on the question https://stackoverflow.com/q/64858513/ asked by the user 'Justin Mayer' ( https://stackoverflow.com/u/11505557/ ) and on the answer https://stackoverflow.com/a/65038256/ provided by the user 'Adam Strauss' ( https://stackoverflow.com/u/11796003/ ) 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: Integer input by user C programming

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.
---
Handling User Input for Integers in C Programming: A Step-by-Step Guide

When programming in C, one common task is to get input from users. Sometimes, the inputs need to be validated to ensure they meet specific requirements—in this case, to verify if the input is an integer. The goal of this guide is to transform a "single-use" input program into a user-friendly loop that continues to prompt the user until they provide a valid integer input. Let’s dive into how to tackle this challenge!

The Problem

You have a simple C program that does the following:

Prompts the user for an integer input.

Checks if the input is valid (an integer followed by the Enter key).

Displays an error message if the input is invalid or empty.

Currently, this program only runs once and doesn't continue asking for valid input. The desired outcome is to have the program continue asking until a valid integer is provided. This can be achieved using a loop, and we will examine how to implement both a do-while loop and a while loop.

The Solution

To address the problem, we need to understand how to implement loops to validate user input effectively. Below, we'll present two methods: using a do-while loop and a while loop.

Using a do-while Loop

A do-while loop ensures that your code block executes at least once before checking the condition for further execution. Here’s how it looks:

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

Breakdown:

The do block executes first, prompting the user for input.

The input is evaluated, and if it’s invalid, an error message is displayed and the input buffer is cleared.

This continues until valid input is received.

Using a while Loop

If you'd rather use a while loop, you need to establish the input condition before entering the loop. Here's the code:

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

Breakdown:

The program prompts for user input once before entering the while loop.

The loop checks if the input is valid and, if not, presents an error and prompts again.

This continues until a valid integer is entered.

Conclusion

Validating user input is crucial for ensuring your program runs smoothly and as expected. By implementing either the do-while or while loop, you can effectively prompt users until they provide a valid integer input. This not only enhances user experience but also strengthens the robustness of your program.

Feel free to choose the method you prefer based on your use case. Both effectively validate input and ensure user engagement. Happy coding!