Is it possible to dynamically build variables in Javascript

Question

I am trying to figure out the best way to dynamically build variables. I have a database that looks like this:

One record:

ans1
ans2
ans3

res1
res2
res3

I have a function that checks the answer against the button the user pressed.

checkAnswer(q, a, $event) {
    if(a == q.correct){
        this.correctanswer = q.success
    }
}

The variable 'a' is either 1, 2 or 3

I would like the code to look something like this:

this.correctanswer = q.res+a

However, this is not working. How can I look up the appropriate response based on the answer the user chooses? So if the user presses answer 1 they see res1 and so on.

it doesn't what that needs to end up being is q.res1 if the user chose answer 1 — Jason, Feb 10 '19 at 22:40
`this` is in reference to what? Please show a little more code. I think its probably something real simple. — yardpenalty.com, Feb 10 '19 at 22:41
we can ignore `this` for now as it is not necessary for my request — Jason, Feb 10 '19 at 22:42
Use `[]` notation for variable property names.... `q['res'+a]` — charlietfl, Feb 10 '19 at 22:42

Jack Bashford · Accepted Answer · 2019-02-10T22:45:20.657

3

Use [] (square bracket notation):

this.correctanswer = q["res" + a];

edited Feb 10 '19 at 22:45

answered Feb 10 '19 at 22:43

Jack Bashford

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`res` should be string – charlietfl Feb 10 '19 at 22:44
Sorry @charlietfl, fixed now. – Jack Bashford Feb 10 '19 at 22:45
You were correct. I can't believe I completely forgot about square bracket notation. thank you – Jason Feb 10 '19 at 22:50
Yes, I was waiting for Stackoverflow to allow me :) – Jason Feb 10 '19 at 23:13

Is it possible to dynamically build variables in Javascript

1 Answers1