js 真值表 nullundefinedfalse"false"Boolean(false)[][[]]""String("")0Number(0)"0"String("0")[0]true"true"Boolean(true)1Number(1)"1"String("1")[1]-1Number(-1)"-1"String("-1")[-1]Infinity-InfinityObject()NaNnullundefinedfalse"false"Boolean(false)[][[]]""String("")0Number(0)"0"String("0")[0]true"true"Boolean(true)1Number(1)"1"String("1")[1]-1Number(-1)"-1"String("-1")[-1]Infinity-InfinityObject()NaN=====>= && <=>=<=else