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CustomStateSet: add() method

Baseline 2024
Newly available

Since ⁨May 2024⁩, this feature works across the latest devices and browser versions. This feature might not work in older devices or browsers.

The add method of the CustomStateSet interface adds value representing a custom state to the CustomStateSet.

Custom elements with a specific state can be selected using the :state() pseudo-class, specifying the desired state as an argument.

Syntax

add(value)

Parameters

value

A string that represents the custom state.

Return value

Undefined.

Examples

The following function adds the state checked to a CustomStateSet.

class MyCustomElement extends HTMLElement {
  set checked(flag) {
    if (flag) {
      this._internals.states.add("checked");
    }
  }
}

Specifications

Browser compatibility

Desktop Mobile
Chrome Edge Firefox Opera Safari Chrome Android Firefox for Android Opera Android Safari on IOS Samsung Internet WebView Android WebView on iOS
add 90 90 126 76 17.4 90 126 64 17.4 15.0 90 17.4

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https://developer.mozilla.org/en-US/docs/Web/API/CustomStateSet/add