The TreeWalker.previousSibling() method moves the current Node to its previous sibling, if any, and returns the found sibling. I there is no such node, return null and the current node is not changed.
USVString corresponds to the set of all possible sequences of unicode scalar values. USVString maps to a String when returned in JavaScript; it's generally only used for APIs that perform text processing and need a string of unicode scalar values to operate on.
The Window.cancelIdleCallback() enables you to cancel a callback previously scheduled with Window.requestIdleCallback.
Returns the element (such as <iframe> or <object>) in which the window is embedded, or null if the element is either top-level or is embedded into a document with a different script origin; that is, in cross-origin situations.
Returns the window itself, which is an array-like object, listing the direct sub-frames of the current window.
Attempts to get the user's attention. How this happens varies based on OS and window manager.
Returns the number of frames (either <frame> or <iframe> elements) in the window.
The window.requestIdleCallback() method queues a function to be called during a browser's idle periods. This enables developers to perform background and low priority work on the main event loop, without impacting latency-critical events such as animation and input response. Functions are generally called in first-in-first-out order unless the function's timeout is reached before the browser calls it.
The flashModes property is an Array of strings identifying each of the flash modes supported by the camera. Possible values are auto, off, on or torch.