BrowserVersionOwn?TypeAs String
Chrome86.0.4240???
Edge86.0.622???
Firefox78.0.0???
Firefox79.0.0ownfunctionfunction FileSystem() { [native code] }
IE7.0.0???
Safari10.1.2???
Safari12.0.0ownfunctionfunction FileSystem() { [native code] }

PropertiesChromeEdgeFirefoxIESafari
length?? 79.0.0? 12.0.0
prototype?? 79.0.0? 12.0.0