Returns a node from a NodeList by index. This method doesn't throw exceptions as long as you provide arguments; a value of null is returned if the index is out of range and a TypeError is thrown if no argument is provided.
The clearMarks() method removes the named mark from the browser's performance entry buffer. If the method is called with no arguments, all performance entries with an entry type of "mark" will be removed from the performance entry buffer.
The clearMeasures() method removes the named measure from the browser's performance entry buffer. If the method is called with no arguments, all performance entries with an entry type of "measure" will be removed from the performance entry buffer.
The clearResourceTimings() method removes all performance entries with an entryType of "resource" from the browser's performance data buffer and sets the size of the performance data buffer to zero. To set the size of the browser's performance data buffer, use the Performance.setResourceTimingBufferSize() method.
The getEntries() method returns a list of PerformanceEntry objects for a given filter. The list's members (entries) can be created by making performance marks or measures (for example by calling the mark() method) at explicit points in time.
The getEntriesByName() method returns a list of PerformanceEntry objects for the given name and type. The list's members (entries) can be created by making performance marks or measures (for example by calling the mark() method) at explicit points in time.
The getEntriesByType() method returns a list of PerformanceEntry objects for a given type. The list's members (entries) can be created by making performance marks or measures (for example by calling the mark() method) at explicit points in time.
The measure() method creates a named timestamp in the browser's performance entry buffer between two specified marks (known as the start mark and end mark, respectively). The named timestamp is referred to as a measure.
The setResourceTimingBufferSize() method sets the browser's resource timing buffer size to the specified number of "resource" performance entry type objects.
The PushManager.hasPermission() method of the PushManager interface returns a Promise that resolves to the PushPermissionStatus of the requesting webapp, which will be one of granted, denied, or default.
The RandomSource.getRandomValues() method lets you get cryptographically random values. The array given as the parameter is filled with random numbers (random in its cryptographic meaning).