how can I change the js built-in objects properties?

Question

I do this: Element.toggle = Element.classList.toggle and I get an error. how can I do this in the right way? thanks.

Answer 1

You can add to the HTMLElement prototype

 HTMLElement.prototype.toggle = function (cls, flag) { this.classList.toggle(cls, flag) } var test = document.querySelector("#test") test.toggle('yellow')

 div.yellow { background-color: yellow; }

 <div id="test">Hello</div>