PropertiesChromeCriOSEdgeFirefoxGooglebotIEOperaSafariSamsungBrowser
length 27.0.1453? 12.0.0 27.0.0??? 3.0.0 6.0.0
prototype 27.0.1453? 12.0.0 27.0.0??? 3.0.0 6.0.0
toString??? 27.0.0?????