Array Update Operators in MongoDB
From the MongoDB cheat sheet · Update Operators · verified Jul 2026
Array Update Operators
Modify array fields in documents
javascript
// Add to array
db.users.updateOne(
{ _id: userId },
{
$push: { tags: "premium" },
$addToSet: { hobbies: "reading" } // No duplicates
}
)
// Add multiple items
db.posts.updateOne(
{ _id: postId },
{
$push: {
comments: {
$each: [comment1, comment2],
$sort: { date: -1 },
$slice: 10 // Keep only 10 newest
}
}
}
)
// Remove from array
db.users.updateOne(
{ _id: userId },
{
$pull: { tags: "old" },
$pop: { history: -1 } // Remove first (-1) or last (1)
}
)💡 $addToSet prevents duplicate values
📌 $ positional operator updates matched element
⚡ $push with $each for bulk array updates
⚠️ $pull removes ALL matching elements
🔗 Related: $pullAll, $pushAll (deprecated)
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