PropertiesChromeCriOSEdgeFirefoxGooglebotIEOperaSafariSamsungBrowser
length 27.0.1453? 12.0.0???? 3.0.0 4.0.0
prototype 27.0.1453? 12.0.0???? 3.0.0 4.0.0
toString 43.0.2357??????? 4.0.0