array.find() 返回未定义

Question

I am trying to update a given subdocument inside an array using its id but when i use the vanila javascript array.find() i get undefined. below is the code

    let offers = service.offers
    console.log("OFFERS ARE ==========", offers)
    
    const offerIDObject = mongoose.Types.ObjectId(offerID)
    console.log("CONVERTED  ID IS ==========", offerIDObject)

    // Find returns undefined for some reason
    const offer = offers.find((el) => {
        return el._id === offerIDObject
    })
    
    offers.map((el, i) =>console.log("ARE OF SAME TYPES======", typeof(el._id) === typeof(offerIDObject)))

    console.log("THE FOUND OFFER IS=======",offer)

What could be the problem with the find method?

Answer 1

objectIds are never the same. you can convert it to string, then compare them like this: return el._id.toString() === offerIDObject.toString() or use mongoose.equals() method:

const offer = offers.find((el) => {
        return el._id.equals(offerIDObject)    
})

both should work.