HTMLElement: style property
Baseline Widely available
This feature is well established and works across many devices and browser versions. It’s been available across browsers since September 2015.
The read-only style
property of the HTMLElement
returns the inline style of an element in the form of a live CSSStyleDeclaration
object that contains a list of all styles properties for that element with values assigned only for the attributes that are defined in the element's inline style
attribute.
Shorthand properties are expanded. If you set style="border-top: 1px solid black"
, the longhand properties (border-top-color
, border-top-style
, and border-top-width
) are set instead.
This property is read-only, meaning it is not possible to assign a CSSStyleDeclaration
object to it. Nevertheless, it is possible to set an inline style by assigning a string directly to the style
property. In this case the string is forwarded to CSSStyleDeclaration.cssText
. Using style
in this manner will completely overwrite all inline styles on the element.
Therefore, to add specific styles to an element without altering other style values, it is generally preferable to set individual properties on the CSSStyleDeclaration
object. For example, you can write element.style.backgroundColor = "red"
.
A style declaration is reset by setting it to null
or an empty string, e.g., elt.style.color = null
.
Note: CSS property names are converted to JavaScript identifier with these rules:
- If the property is made of one word, it remains as it is:
height
stays as is (in lowercase). Asfloat
is a reserved keyword in JavaScript, this property name was historically converted tocssFloat
. All modern browsers now support the direct use offloat
in JavaScript to access thefloat
CSS property, butcssFloat
is used in older browsers and is still supported as an alias in modern browsers. - If the property is made of several words, separated by dashes, the dashes are removed and it is converted to camel case:
background-attachment
becomesbackgroundAttachment
.
The style
property has the same priority in the CSS cascade as an inline style declaration set via the style
attribute.
Value
A live CSSStyleDeclaration
object.
Examples
Getting style information
The following code snippet demonstrates how the values obtained using the element's style
property relates to the style set on the HTML attribute:
<!doctype html>
<html lang="en-US">
<body style="font-weight:bold">
<div style="border-top: 1px solid blue; color:red" id="elt">
An example div
</div>
<pre id="out"></pre>
</body>
</html>
const element = document.getElementById("elt");
const out = document.getElementById("out");
const elementStyle = element.style;
// We loop through all the element's styles using `for...in`
for (const prop in elementStyle) {
// We check if the property belongs to the CSSStyleDeclaration instance
// We also ensure that the property is a numeric index (indicating an inline style)
if (
Object.hasOwn(elementStyle, prop) &&
!Number.isNaN(Number.parseInt(prop))
) {
out.textContent += `${
elementStyle[prop]
} = '${elementStyle.getPropertyValue(elementStyle[prop])}'\n`;
}
}
Note font-weight
is not listed as a value for elementStyle
as it is not defined within the style
attribute of the element itself. Rather, it is inherited from the definition on its parent. Also note that the shorthand border-top
property, defined in the style
attribute, is not listed directly. Rather, it is replaced by the three corresponding longhand properties (border-top-color
, border-top-style
, and border-top-width
).
Specifications
Specification |
---|
CSS Object Model (CSSOM) # dom-elementcssinlinestyle-style |
Browser compatibility
BCD tables only load in the browser