Mongoose - How To Remove Object From Array Element

Question

A user has the ability to add languages. languages are stored as an array of type teach or learn in the userschema. I can simply add a language to the languages.teach[] by using push, but how do i remove one?

language object example

let language = {
    "code": FR
    "level": 1
};

UserScema.js

var UserSchema = new Schema({

        email: {
            value: {
                type: String,
                lowercase: true,
                //unique: true,

            },
            token: String,
            verified: Boolean,
        },
        password: {
            type: String,
        },

        phone: {
            countryCode: {
                type: String,
                //required:true,
                unique: true,
            },
            number: {
                type: String,
                required: true
            },
            code: String,
            verified: {
                type: Boolean,
                default: false
            },
        },

        jwt: String,

        profile: {
            username: String,
            firstname: String,
            lastname: String,
            dob: String,
            level: Number,
            location: String,
            image: String,
            introduction: String,
        },
        languages: {
            teach: [],
            learn: [],
        }
    },
    {
        timestamps: {createdAt: 'created_at', updatedAt: 'updated_at'}
    });

LanguagesController.js

destroy(req, res) {

    let id       = req.params.id;
    let language = {
        "code": req.body.code,
        "level": req.body.level
    };
    let type     = req.params.type;

    User.findOne({'_id': id}, function (err, user) {

        if (err) {
            return res.status(404).json({

                success: true,
                status: 404,
                data: err,
                message: "User does not exist",

            });
        }

        if (type === "teach") {

            for (let i = 0; i < user.languages.teach.length; i++)
                if (user.languages.teach[i].code === language.code) {
                    user.languages.teach[i].remove();
                    break;
                }

        }
        if (type === "learn") {
            //user.languages.learn.push(language);
        }

        console.log(user);

        user.save((err, user) => {

            return res.status(200).json({

                success: true,
                status: 201,
                data: user,
                message: "Successfully Deleted Language",

            });
        });

    });

}

I tried to use .remove but im getting a user.languages.teach[i].remove is not a function.

try `user.languages.teach = user.languages.teach.filter( o => o.code !== language.code)` instead of your for loop inside `if (type === "teach")` — Raghav Garg, Sep 17 '17 at 09:55
what does that do, im using type because i want to change the language array depending on user input, use the same code if thy want to manipulate type == teach or type ==learn.. — Kay, Sep 17 '17 at 10:02
sorry if i was not clear, but i am not saying to remove your if condition, i was saying to remove your for loop inside the `if (type === "teach")` with my above given snippet. — Raghav Garg, Sep 17 '17 at 10:04

score 2 · Accepted Answer · answered Sep 17 '17 at 10:11

2

Yes .remove is nothing on the array. You can use .filter to remove unwanted array elements.

It would be used like:

if (type === "teach") {
    user.languages.teach = user.languages.teach.filter( o => o.code !== language.code)
}

This will remove all the element from the array with the condition given above.

Mongoose - How To Remove Object From Array Element

2 Answers2