PropertiesChromeCriOSEdgeFirefoxGooglebotIEOperaSafariSamsungBrowser
length 15.0.874?? 18.0.0 2.1.0?? 4.0.0?
prototype 15.0.874? 13.10586.0 18.0.0 2.1.0 10.0.0? 4.0.0?
toString 15.0.874?? 24.0.0 2.1.0?? 4.0.0?