一个ObjectId数组中的Mongoose indexOf [英] Mongoose indexOf in an ObjectId array

问题描述

我有以下架构：

var daySchema = new Schema({
date: {
    type: Date,
    required: true
},
activities: [{
    type: Schema.Types.ObjectId,
    ref: 'Activity'
}]
});

我正在删除白天的活动架构：

And I am removing an activity within the daySchema:

var index = day.activities.indexOf("584aa9c16791eb1ec4ad8e73");
day.activities.splice(index, 1);

有人可以解释我为什么这样做吗？。数组活动是 ObjectId的数组。因此， indexOf不应与对象一起使用，但 indexOf仍能够基于id查找元素。这让我发疯，还有其他事情要做，也许是ObjectId中的map函数？

Can someone explain me why this works ?. The array "activities" is an array of "ObjectId". So the "indexOf" should not work with objects, but still the "indexOf" is able to find the element based on the id. This is driving me crazy, is something else going on here, maybe a map function inside ObjectId ?

推荐答案

这是有效的，因为猫鼬包装了 MongooseArray 中的一个数组，它提供了自己的 indexOf 方法支持基于字符串的比较，而不是本机数组实现所使用的严格相等性测试。

This works because Mongoose wraps an array in MongooseArray which provides its own indexOf method which supports this string-based comparison rather than the strict equality test used by the native array implementation.

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