BrowserVersionOwn?TypeAs String
Chrome85.0.4183???
CriOS85.0.4183???
Edge86.0.622???
Firefox68.0.0???
IE10.0.0???
Safari10.1.2ownfunctionfunction UserMessageHandlersNamespace() { [native code] }

PropertiesChromeCriOSEdgeFirefoxIESafari
length????? 10.0.0
prototype????? 10.0.0