标签：条件 怎么 mon ace mil 数组 class src size
1.filter通常情况下是用来返回一个符合条件的新数组的，并且他不会对原数组产生影响：
comment_or_reply_id: "ob8qj0xq8e5s", from_uid: "1502039268@qq.com", isAgreeClick: true, topic_id: "604629fd0344202df0b22d81", topic_type: "nous_articles" }, { comment_or_reply_id: "1", from_uid: "666", isAgreeClick: true, topic_id: "604629fd0344202df0b22d81", topic_type: "nous_articles" } ] let crr = { from_uid: "1502039268@qq.com", comment_id: ‘ob8qj0xq8e5s‘ } let b = arr.filter(function (curentV, index, arr) { return curentV.from_uid == crr.from_uid && curentV.comment_or_reply_id == crr.comment_id }) console.log(b)
运行结果：
[ { comment_or_reply_id: ‘ob8qj0xq8e5s‘, from_uid: ‘1502039268@qq.com‘, isAgreeClick: true, topic_id: ‘604629fd0344202df0b22d81‘, topic_type: ‘nous_articles‘ } ]
但是我只是要拿到里面的isAgreeClick怎么做呢？
这样吗：
let b = arr.filter(function (curentV, index, arr) { return curentV.from_uid == crr.from_uid && curentV.comment_or_reply_id == crr.comment_id })[0].isAgreeClick console.log(b)
运行结果：true，的确拿到了该值，但是此种做法的弊端就是，当filter里面的条件没有匹配到时，会返回一个空数组，此时对空数组取值就会报错！
例子：还是刚才那段代码，但是此时comment_or_reply_id为1了，此时匹配不到就会报错
let arr = [{ comment_or_reply_id: "1", from_uid: "1502039268@qq.com", isAgreeClick: true, topic_id: "604629fd0344202df0b22d81", topic_type: "nous_articles" }, { comment_or_reply_id: "1", from_uid: "666", isAgreeClick: true, topic_id: "604629fd0344202df0b22d81", topic_type: "nous_articles" } ] let crr = { from_uid: "1502039268@qq.com", comment_id: ‘ob8qj0xq8e5s‘ } let b = arr.filter(function (curentV, index, arr) { return curentV.from_uid == crr.from_uid && curentV.comment_or_reply_id == crr.comment_id })[0].isAgreeClick console.log(b)
如何处理呢，下面给出方案：就是把后面数组的返回结果附上布尔值，就可以进行拿到里面的bool值了，但是此种做法只针对布尔值有效，想要拿到里面的其它类型元素的值，
而且在空数组我下仍然不会报错的话，我暂时没有思路。
let b = arr.filter(function (curentV, index, arr) { return curentV.from_uid == crr.from_uid && curentV.comment_or_reply_id == crr.comment_id })==false console.log(b)
上面运行结果：
标签：条件 怎么 mon ace mil 数组 class src size
原文地址：https://www.cnblogs.com/hmy-666/p/14617440.html
