Скачать или смотреть Solving the if statement not working with document.querySelector Issue in JavaScript

Discover how to effectively handle visibility in JavaScript when dealing with DOM elements using `getComputedStyle` instead of inline style checks.
---
This video is based on the question https://stackoverflow.com/q/62763695/ asked by the user 'Praneet Dixit' ( https://stackoverflow.com/u/13606509/ ) and on the answer https://stackoverflow.com/a/62763885/ provided by the user 'Unmitigated' ( https://stackoverflow.com/u/9513184/ ) 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: If statement not working with document.querySelector

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 the Problem: Why Your If Statement Isn't Working with document.querySelector

If you are working on a hamburger menu in JavaScript, you might have encountered a frustrating issue: your if statement does not trigger the changes to the display properties of your menu elements. In this post, we will break down this problem and provide a solution to ensure that your hamburger menu transitions smoothly to a close icon.

The Scenario

Imagine you have created a hamburger menu that, when clicked, transitions from bars to an "X" icon. Initially, your code is structured well, but when you try to add an if statement to manage the display state of the menu, it just doesn't work. Here’s a simplified version of the code that you might be using:

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

Before we jump into the solution, let’s understand why that if statement is not functioning as intended.

The Reason Behind the Problem

The issue stems from how you're checking the display property of the cross element. The style property in JavaScript only reflects inline styles added directly to the element via JavaScript, not the styles that are a result of CSS rules set in a stylesheet. This means if the display property is controlled via CSS, it won't be read properly by your condition.

What This Means for Your Code

The cross.style.display check checks for inline CSS, which is always "" (empty string) because it is not being set inline but rather controlled via the class cross.

The condition will never be true and thus the code block to change the bars and cross display will not execute.

The Solution: Use getComputedStyle Instead

To solve the problem, you should check the computed style of the element instead of relying on the inline style. The getComputedStyle function allows you to retrieve all the styles applied to an element, regardless of whether they are inline or defined in stylesheets. Here’s how you can update your code:

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

Key Points to Remember

Use getComputedStyle for accurate style checks: Always prefer using getComputedStyle for any checks related to display properties or any property that might not be set inline.

Maintain clear variable naming: Ensure your variable names clearly describe their purpose. In this case, naming your elements as bars and cross helps indicate their roles in your menu.

Conclusion

In summary, a common pitfall when working with JavaScript and the DOM is failing to retrieve the correct styles from elements when using document.querySelector. By incorporating window.getComputedStyle, you can accurately manage the display states of your hamburger menu, ensuring a seamless user experience. With this understanding, you now have the tools to troubleshoot similar issues in your JavaScript projects effectively.

For any further queries or if you need additional assistance with your JavaScript projects, feel free to reach out or drop a comment below! Happy coding!