$[identifier]
Reference group: Array update operators
What it does
Updates elements matching the named array filter.
Syntax
array.$[identifier].field + arrayFilters
Use case
Precisely target nested array elements.
Important notes
Array-filter identifiers start with a lowercase letter and contain alphanumeric characters.
$[identifier]: practical example
db.orders.updateOne({ _id: orderId }, { $set: { "items.$[it].checked": true } }, { arrayFilters: [{ "it.quantity": { $gt: 0 } }] })💡 Explanation
Updates elements matching the named array filter.
When to use it
Precisely target nested array elements.
Caution
Array-filter identifiers start with a lowercase letter and contain alphanumeric characters.
Key Takeaways
- Updates elements matching the named array filter.
- Typical use: Precisely target nested array elements.