Скачать или смотреть How to Cancel a JavaScript Prompt Based on User Input

Learn how to effectively use prompts in JavaScript to conditionally cancel actions based on specific user input. Perfect for beginners!
---
This video is based on the question https://stackoverflow.com/q/65187489/ asked by the user 'Ibrahim Ryan' ( https://stackoverflow.com/u/14526035/ ) and on the answer https://stackoverflow.com/a/65188301/ provided by the user 'Manu Sampablo' ( https://stackoverflow.com/u/13891757/ ) 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: Cancel out a prompt if something equals something

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.
---
Understanding JavaScript Prompts: How to Cancel Based on Input

JavaScript prompts are a useful tool when it comes to gathering user input on web applications. However, sometimes you may want to cancel an action based on the user's response. In this article, we'll address a common scenario: how to cancel out a prompt if the input meets a specific condition.

The Problem

Imagine you have a simple web page where you can change the title of the document via a prompt. The original user intended to create a function that changes the document title but wanted to cancel this action when the user input matches a predefined value (in this case, a prompt for a placeholder title "Enter website title..."). How can you achieve that?

The Solution

Here’s how you can modify your JavaScript function to implement this behavior. Let’s break it down into clear steps and provide the working code for you to try.

Step 1: Define Your HTML Structure

First, ensure you have the essential HTML elements in place. You need a button to trigger the function and an h1 tag to display the website title:

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

Step 2: JavaScript Function Implementation

Now, let’s look at the JavaScript code that handles the prompt and title changes. Here's the revised function:

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

Explanation of the Code

Prompt Function: When the button is clicked, a prompt will appear asking the user to input their website title.

Input Check:

If the user provides input (not null), the code checks if that input equals the mainTitle.

If the input does not match, it updates the document title and the h1 text.

If the input matches mainTitle, an alert is shown to indicate that the prompt did not result in a change.

Conclusion

By implementing the approach outlined above, you can successfully control the behavior of prompts in JavaScript, enabling your web applications to behave more intelligently based on user input. This simple logic can significantly enhance the user experience by preventing unwanted changes.

Experiment with the code and customize the behavior according to your needs. Happy coding!