jQuery jQuery.cssNumber Property

Posted in jQuery Tutorial

Updated on May 20, 2024

By Mari Selvan

👁️ 23 - Views

⏳ 4 mins

💬 1 Comment

Photo Credit to CodeToFun

🙋 Introduction

jQuery is a powerful JavaScript library that simplifies the process of working with HTML documents, handling events, and performing animations. One of its lesser-known but highly useful features is the .cssNumber property. This property allows developers to specify which CSS properties should be treated as numbers, ensuring smoother manipulation and animation of these properties.

In this guide, we will explore the .cssNumber property in jQuery, providing a detailed explanation and practical examples to help you understand its usage.

🧠 Understanding jQuery.cssNumber Property

The .cssNumber property in jQuery is an object that contains properties whose values are numbers but do not require a unit (like 'px', '%', etc.). By default, jQuery automatically appends a unit to certain CSS properties, but for others, it recognizes them as unit-less and leaves the value as-is. This is particularly useful for properties like zIndex, fontWeight, and opacity, which are inherently numeric and do not require units.

Default Properties in .cssNumber:

jQuery’s .cssNumber property includes the following properties by default:

animationIterationCount
columnCount
fillOpacity
flexGrow
flexShrink
fontWeight
lineHeight
opacity
order
orphans
widows
zIndex
zoom

💡 Syntax

To access or modify the .cssNumber property, use the following syntax:

syntax.js

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jQuery.cssNumber[propertyName] = true/false;

📝 Example

Understanding the Default Behavior:

By default, jQuery treats properties listed in .cssNumber without adding units. For example, setting the zIndex property:
example.js
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```
$("#myElement").css("zIndex", 10);
```
In this case, jQuery correctly applies the value 10 without appending a unit.
Adding a Custom Property to .cssNumber:

If you want to add a custom property to .cssNumber, you can do so by simply assigning it a value of true. For example, let’s say we have a custom property customOpacity:
example.js
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```
jQuery.cssNumber.customOpacity = true;

$("#myElement").css("customOpacity", 0.75);
```
By setting customOpacity in .cssNumber, jQuery will handle it as a numeric value without appending a unit.
Removing a Property from .cssNumber:

If you need to remove a property from .cssNumber, set it to false:
example.js
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```
jQuery.cssNumber.opacity = false;

$("#myElement").css("opacity", 0.5); // jQuery will append 'px' (which may not work as intended)
```
This is generally not recommended, as it can lead to unexpected behavior.

🎉 Conclusion

The jQuery .cssNumber property is a powerful yet underutilized feature that ensures numeric CSS properties are handled correctly without unnecessary units. Understanding and using this property can help you manipulate CSS properties more effectively, leading to cleaner and more efficient code. Whether you're working with default properties or adding custom ones, .cssNumber provides a straightforward way to manage numeric CSS values in jQuery.

By mastering this property, you can enhance your web development projects with precision and ease.