CSSStyleDeclaration

Baseline Widely available

This feature is well established and works across many devices and browser versions. It’s been available across browsers since July 2015.

The CSSStyleDeclaration interface is the base class for objects that represent CSS declaration blocks with different supported sets of CSS style information:

CSSStyleProperties — CSS styles declared in stylesheet (CSSStyleRule.style), inline styles for an element such as HTMLElement, SVGElement, and MathMLElement, or the computed style for an element returned by Window.getComputedStyle().
CSSPageDescriptors — Styles for CSS at-rules.

The interface exposes style information and various style-related methods and properties. For example, it provides getPropertyValue() for getting the value of a dash-named CSS property, such as border-top, which can't be directly accessed using dot notation because of the hyphens in its name.

Note: Earlier versions of the specification used CSSStyleDeclaration to represent all CSS declaration blocks, and some browsers and browser versions may still do so (check the browser compatibility tables for the above APIs). Generally the same website code will be functional in both old and new versions, but some properties returned in a CSSStyleDeclaration may not be relevant in a particular context.

Attributes

CSSStyleDeclaration.cssText

Textual representation of the declaration block, if and only if it is exposed via HTMLElement.style. Setting this attribute changes the inline style. If you want a text representation of a computed declaration block, you can get it with JSON.stringify().

CSSStyleDeclaration.length Read only

The number of properties. See the item() method below.

CSSStyleDeclaration.parentRule Read only

The containing CSSRule.

CSS Properties

CSSStyleDeclaration.cssFloat

Special alias for the float CSS property.

CSSStyleDeclaration named properties

Dashed and camel-cased attributes for all supported CSS properties.

Instance methods

CSSStyleDeclaration.getPropertyPriority()

Returns the optional priority, "important".

CSSStyleDeclaration.getPropertyValue()

Returns the property value given a property name.

CSSStyleDeclaration.item()

Returns a CSS property name by its index, or the empty string if the index is out-of-bounds.

CSSStyleDeclaration.removeProperty()

Removes a property from the CSS declaration block.

CSSStyleDeclaration.setProperty()

Modifies an existing CSS property or creates a new CSS property in the declaration block.

CSSStyleDeclaration.getPropertyCSSValue()

Only supported via getComputedStyle in Firefox. Returns the property value as a CSSPrimitiveValue or null for shorthand properties.

Example

js
const styleObj = document.styleSheets[0].cssRules[0].style;
console.log(styleObj.cssText);

for (let i = styleObj.length; i--; ) {
  const nameString = styleObj[i];
  styleObj.removeProperty(nameString);
}

console.log(styleObj.cssText);