If a type that’s T | null or T | null | undefined, we use non-null assertion operator ! to tell TS that we’re sure it’s not null | undefined:
function removeFromDOM(element: Element){
// element.parentNode.removeChild(element); // 'element.parentNode' is possibly 'null'.
element.parentNode!.removeChild(element);
}
let id = 'testId';
// removeFromDOM(document.getElementById(id)); // Argument of type 'HTMLElement | null' is not assignable to parameter of type 'Element'.
removeFromDOM(document.getElementById(id)!);