咏竹莉
where there is a will,there is a way
摘要: let a = undefined let b = null let c = '' if (a == undefined) { alert('undefined') // alert undefined 成立 } if (b == undefined) { alert('undefined') // 阅读全文
posted @ 2021-04-02 11:05 咏竹莉 阅读(1389) 评论(0) 推荐(0)