HTMLOptionElement: selected property

The selected property of the HTMLOptionElement interface specifies the current selectedness of the element; that is, whether the <option> is selected or not.

The presence of the HTML selected attribute indicates the option is selected by default. It does not indicate whether this option is currently selected: if the option's state changes, the selected content attribute does not reflect the change; only the HTMLOptionElement's selected IDL property is updated. The selected attribute is reflected by the defaultSelected property.

const optionElement = document.getElementById("water");
console.log(optionElement.selected);