How do I remove a string from an array in a mongodb document?

Question

I've been having trouble with the problem of removing a string from an array in a mongodb document. For example I want to remove the entry "four" from the list field in the document below.

{
  "list" : [ "1", "2", "four", "five", "6"]
}

I know it seems very simple but I haven't been able to find a straight answer from the docs or previous questions. I've tried 5 or so commands to no avail using db.collection.update combined with the $pull and $mod modifiers. Any help?

I know, very rudimentary question.

Answer 1

You can use $pull operator, please try the below query:

db.collection.update({
    { _id : id },
    { $pull: { "list": "four" } }
});

If you want to remove two or more elements from the array "list", you can do that with $pull operator, as well:

db.collection.update({
    { _id : id },
    { $pull: { list : { $in : [ "one", "four" ] } } }
});