This feature is not Baseline because it does not work in some of the most widely-used browsers.
The append() method of the StylePropertyMap interface adds the passed CSS value to the StylePropertyMap with the given property.
append(property, value)
propertyAn identifier indicating the stylistic feature (e.g., font, width, background color) to add.
valueThe value the given property should have.
None (undefined).
This example shows an extra background image value being added to the background-image property of the element, using HTMLElement.attributeStyleMap.
// get the button element
const buttonEl = document.querySelector("button");
// append another value to the background-image property set on the attribute
buttonEl.attributeStyleMap.append(
"background-image",
"linear-gradient(180deg, blue, black)",
);
| Specification |
|---|
| CSS Typed OM Level 1> # dom-stylepropertymap-append> |
| Desktop | Mobile | |||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Chrome | Edge | Firefox | Opera | Safari | Chrome Android | Firefox for Android | Opera Android | Safari on IOS | Samsung Internet | WebView Android | WebView on iOS | |
append |
66 | 79 | No | 53 | 16.4 | 66 | No | 47 | 16.4 | 9.0 | 66 | 16.4 |
© 2005–2025 MDN contributors.
Licensed under the Creative Commons Attribution-ShareAlike License v2.5 or later.
https://developer.mozilla.org/en-US/docs/Web/API/StylePropertyMap/append