请教各位大神，用mongoose如何获取最新插入的一条数据的id

Posted 2023-05-08

参考技术A Kitten.find(function(err, data) console.log(data); ); 你确定不需要查询条件？model.find(,function) mongoose 会把表名变成复数。你的 jj 不懂是不是被它变成了 jjs

各位js大神,请教以下如下俩个对象数组如何合并为一个？

arr1:
["msg":"你也好","from":"libai","msg":"我是李白,你是谁","from":"libai"]
arr2:
["msg":"你好","from":"admin","msg":"LOL吗","from":"admin","msg":"我是系统管理员,你是李白吗","from":"admin"]
我想让合并后的数组为
["msg":"你也好","from":"libai","msg":"我是李白,你是谁","from":"libai","msg":"你好","from":"admin","msg":"LOL吗","from":"admin","msg":"我是系统管理员,你是李白吗","from":"admin"]
,应该调用什么方法呢

参考技术A

js的数组合并有三种方法，任何一种都可以做到你需要的结果，如下：

concat 方法

var arr1=["msg":"你也好","from":"libai","msg":"我是李白,你是谁","from":"libai"];

var arr2=["msg":"你好","from":"admin","msg":"LOL吗","from":"admin","msg":"我是系统管理员,你是李白吗","from":"admin"];

var arr=arr1.concat(arr2);

console.log(c);//你要的结果，不改变arr1和arr2

循环遍历

var arr1=["msg":"你也好","from":"libai","msg":"我是李白,你是谁","from":"libai"];

var arr2=["msg":"你好","from":"admin","msg":"LOL吗","from":"admin","msg":"我是系统管理员,你是李白吗","from":"admin"];

for(var i=0;i<arr2.length;i++)

    arr1.push(arr2[i]);

console.log(arr1);//你要的结果，但是这个是直接改变了arr1这个数组

apply方法

合并数组arr1和数组arr2,使用Array.prototype.push.apply(arr1,arr2)  or arr1.push.apply(arr1,arr2);

var arr1=["msg":"你也好","from":"libai","msg":"我是李白,你是谁","from":"libai"];

var arr2=["msg":"你好","from":"admin","msg":"LOL吗","from":"admin","msg":"我是系统管理员,你是李白吗","from":"admin"];

Array.prototype.push.apply(arr1,arr2); //或者 arr1.push.apply(arr1,arr2);

console.log(arr1) //改变了arr1

   

参考技术B eq.
[...arr1, ...arr2]
eq.
arr1.contact(arr2)