PropertiesChromeCriOSEdgeFirefoxGooglebotIEOperaSafariSamsungBrowser
length 15.0.874? 16.0.0 48.0.0??? 3.0.0?
prototype 15.0.874? 16.0.0 48.0.0??? 3.0.0?
toString 15.0.874?????? 4.0.0?