Java script how to construct an object using variables

Question

I'm working on express.js framework and sequlize.js orm.

I get the region and the type from the back-end.

Using those two variables I want to construct an object to pass to the sequlize orm.

        let region_id = req.swagger.params.region_id.value;
        let type = req.swagger.params.type.value;

        console.log("REGION", region_id) // will output 4,5,6,... etc
        console.log("TYPE", type) // will output is_lunch,is_dinner,... etc

That was my variables.

This is my object

const prepared_query = {
            where:{
            },
            attributes: ['price'],
            include: [{
                model: db.restaurants,
                attributes: ['region_id'],
                where: {
                    region_id: ''
                }
            }]
        }

        prepared_query.include[0].where.region_id = region_id;
        prepared_query.where[type] = true;

prepared_query.include[0].where.region_id = region_id;

successfully replaced the region_id as 4. but

prepared_query.where[type] = true;

is not gives me is_lunch:true' instead it gives me Cannot set property 'is_lunch' of undefined

HOW DO I ACHIEVE THIS USING JAVA SCRIPT?

Possible duplicate of [Dynamically access object property using variable](https://stackoverflow.com/questions/4244896/dynamically-access-object-property-using-variable) — Nisarg Shah, Sep 05 '18 at 09:20
You should try doing `prepared_query[type] = true;` Let me know if that doesn't work. — Nisarg Shah, Sep 05 '18 at 09:25
@NisargShah Thanks a lot. I din't heard this thing before =) — margherita pizza, Sep 05 '18 at 10:10

score 0 · Answer 1 · answered Sep 05 '18 at 09:26

0

you can do this.

prepared_query.include[0].where.region_id = region_id;
prepared_query[type] = true;

object.property = value;
{
    //static
    "property": value;
}
object[property] = value;
{
    //dynamic
    [property]: value;
}

read this page: https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Operators/Property_Accessors

answered Sep 05 '18 at 09:26

seunggabi

1,699
12
12

Thanks a lot. I din't heard this thing before =) – margherita pizza Sep 05 '18 at 10:10
@PathumSamararathna this is async problem, so you use `await - async` async ajaxfunction() .. res = await getResponse() – seunggabi Sep 05 '18 at 10:15

score 0 · Answer 2 · answered Sep 05 '18 at 10:09

0

I didn't set anything to the prepared_query.where was the problem here.

    prepared_query.where = {};
    prepared_query.where[type] = true

Gives me the correct output.

answered Sep 05 '18 at 10:09

margherita pizza

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Java script how to construct an object using variables

2 Answers2