javascript boolean variable's value is not changing

Question

I have a variable called itemExist and set that equal to false. My goal is to set this variable's value to true if a condition happens. My code is this:

var itemExist = false;

        user.findById({_id: decoded._id}).populate('shoppingCart').exec((err, items)=>{
            items.shoppingCart.forEach(async item=>{
                if(item.productId == productId){
                    itemExist = true;

When I console log the itemExist variable outside of all theese functions

console.log(itemExist);

I get that result on the console:

false

But it should be true. How can I solve this problem, what is causing that?

Javascript are async, so, try to put console inside the promise. If works, there's no problem, just a little confusion on your execution plan... — rpereira15, Feb 01 '20 at 14:23

Pasha · Answer 1 · 2020-02-03T08:48:00.000

0

Perform your work inside exec function

user.findById({_id: decoded._id}).populate('shoppingCart').exec((err, items)=> 
    {
        const itemInArr = items.shoppingCart.find(item => item.productId === productId);
        //!! - convertation to boolead value
        itemExist = !!itemInArr;
        console.log(itemExist);
    }
);

edited Feb 03 '20 at 08:48

answered Feb 01 '20 at 14:44

Pasha

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javascript boolean variable's value is not changing

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