HTMLElement: style property

{{APIRef("CSSOM")}}

The read-only style property of the {{domxref("HTMLElement")}} returns the inline style of an element in the form of a live {{domxref("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 ({{cssxref("border-top-color")}} , {{cssxref("border-top-style")}} , and {{cssxref("border-top-width")}} ) are set instead.

This property is read-only, meaning it is not possible to assign a {{domxref("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 {{domxref("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 {{domxref("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). As float is a reserved keyword in JavaScript, this property name was historically converted to cssFloat. All modern browsers now support the direct use of float in JavaScript to access the float CSS property, but cssFloat 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 {{Glossary("camel_case", "camel case")}} : background-attachment becomes backgroundAttachment.

The style property has the same priority in the CSS cascade as an inline style declaration set via the style attribute.

Value

A live {{domxref("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`;
  }
}

{{EmbedLiveSample("Getting_style_information", "100", "130")}}

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 {{cssxref("border-top")}} property, defined in the style attribute, is not listed directly. Rather, it is replaced by the three corresponding longhand properties ({{cssxref("border-top-color")}} , {{cssxref("border-top-style")}} , and {{cssxref("border-top-width")}} ).

Specifications

{{Specifications}}

Browser compatibility

{{Compat}}

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