Mongodb $in against a field of objects of array instead of objects of array

Question

arr=[{field1:,field2:

I want to use the $in operator against the field1 of arr. I

Answer 1

Extending Neil Lunn's answers, you can use map function within query also.

var arr = [
    { "name": "foo", "location": "NY"},
    { "name": "bar", "location": "LA"},
    { "name": "foobar", "location": "NZ"}
];

db.collection.find({ "fieldx": { "$in": arr.map(function(x) { return x.location } ) } })

If you using ES6 syntax then

db.collection.find({ "fieldx": { "$in": arr.map(x => x.location ) } })