CustomStateSet: add() method

{{APIRef("Web Components")}}

The add method of the {{domxref("CustomStateSet")}} interface adds value representing a custom state to the CustomStateSet.

Custom elements with a specific state can be selected using the {{cssxref(":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

{{Specifications}}

Browser compatibility

{{Compat}}