Remove from array[ObjectId]

Hello,

How can I remove a ObjectId from a array of ObjectId ?

My model :

var User = new Schema({
    title       : { type : String,  index: true },
    name        : String,
    friends     : [ObjectId],
    join_at     : {type:Date, default:Date.now },
    save_at     : {type:Date, default:Date.now }
});

The function for deleting the objectId : uid

User.findOne({'_id' : self.id}, function(err, me){
    for(var i=0; i<=me.friends.length; i++){
        if (String(me.friends[i])==String(uid)){
            me.friends.splice(i, 1);
            break;                          
        }
    }
    me.save(function(err,us){
        next(err,'kljlmjk'+JSON.stringify(me));
    });     
});                                     

Thanks for your response.

[bnoguchi]

Don’t use splice.

me.friends.remove(uid);
me.save(callback);

[nghuuphuoc]

Is there a way to do this to multiple documents as following?

User.update({
    friends: uid
}, {
    '$pull': {
        friends: uid
    }
})