Note: This feature is available in Web Workers.
The StylePropertyMapReadOnly.keys() method returns a new array iterator containing the keys for each item in StylePropertyMapReadOnly.
keys()None.
A new Array.
In this example, we use the keys() method to access the properties within the Element.computedStyleMap().
// get a button element
const buttonEl = document.querySelector("button");
// we can retrieve all computed styles with `computedStyleMap`
const allComputedStyles = buttonEl.computedStyleMap();
// keys returns an iterable list of properties
const props = allComputedStyles.keys();
console.log(props.next().value); // returns align-content