Скачать или смотреть How to Add Event Listener to Multiple Inputs with the Same Class

Learn how to effectively manage input fields in JavaScript by adding event listeners that work on multiple elements sharing the same class.
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Mastering Event Listeners for Multiple Input Fields

If you've recently dived into web development, you might be coming across scenarios where you need to enhance user interactions on your forms. A common challenge arises when you want to apply the same behavior across multiple input fields that share the same class. In this guide, we'll tackle this problem head-on, focusing on how to add an event listener to multiple inputs and achieve the desired user experience.

The Problem

Let’s say you have styled your input fields elegantly with HTML and CSS. You have a label that you want to shrink when the input field is focused or filled. However, the current code only allows this behavior on the first input field due to a limitation in how event listeners are applied. Here’s a quick breakdown of the scenario:

HTML Structure: You have multiple input fields, all assigned a class name for easy selection.

CSS Stylings: Styling for the labels shrinks when the inputs are focused.

JavaScript Limitation: Your existing JavaScript code targets only the first element, leaving others unaffected.

The ultimate question is: How can you fix this?

The Solution

To make sure all input fields react appropriately, you'll want to utilize the querySelectorAll method instead of querySelector. This method allows you to select all elements that match a specific selector, making it perfect for our needs.

Step-by-Step Implementation

Select All Input Fields: You can use document.querySelectorAll to grab all inputs you need to apply the listener to.

Loop Through the Selected Elements: Using forEach, you can iterate through each input and attach an event listener.

Define the Shrink Function: The function will check if the input has any value and apply or remove a class that controls the styling.

Here’s how your updated JavaScript code should look:

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

How It Works

Event Listener Setup: By using querySelectorAll, we target all input elements with the specified class. This change means that every input will now have an event listener attached to it.

Dynamic Label Adjustment: As users type in any of the input fields, the shrinkLabel function dynamically adjusts the corresponding label based on the input's value.

CSS Reminders

Ensure your CSS is set up properly for the shrink class so your labels adjust their position and styling:

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

Conclusion

Incorporating user-friendly interfaces in your web applications can significantly improve user experience. By following these steps to apply an event listener to multiple input fields with the same class, you can ensure a consistent and polished look for your forms.

With the solution in hand, you can now confidently implement similar behaviors across all your input fields, making your forms more interactive. Happy coding!