toString.call(1)
"[object Number]"
toString.call(true)
"[object Boolean]"
toString.call(Object)
"[object Function]"
toString.call([])
"[object Array]"
toString.call(undefined)
"[object Undefined]"
toString.call('undefined')
"[object String]"
toString.call(1)
"[object Number]"
toString.call(true)
"[object Boolean]"
toString.call(Object)
"[object Function]"
toString.call([])
"[object Array]"
toString.call(undefined)
"[object Undefined]"
toString.call('undefined')
"[object String]"