記得看不懂的都丟到babel上面試試
任何數字加上 undefined 都會是 NaN
空字串是falsey.
(The values false
, null
, 0
, ""
, undefined
, and NaN
are falsey)
驗證是否為空字串
記得看不懂的都丟到babel上面試試
任何數字加上 undefined 都會是 NaN
空字串是falsey.
(The values false
, null
, 0
, ""
, undefined
, and NaN
are falsey)
驗證是否為空字串
JavaScript