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Tag: javascript

Mongoose JS findOne always returns null

I’ve been fighting with trying to get Mongoose to return data from my local MongoDB instance; I can run the same command in the MongoDB shell and I get results back. I have found a post on stackoverflow that talks about the exact problem I’m having here; I’ve followed the answers on this pos…

React form onChange->setState one step behind

I encountered this problem building a webapp and I replicated it in this jsfiddle. Essentially, I would like an input to call this.setState({message: input_val}) every time I type something into it, then pass it into the parent App class which then re-renders the message onto the Message class. However the ou…

Transforming a Javascript iterable into an array

I’m trying to use the new Map object from Javascript EC6, since it’s already supported in the latest Firefox and Chrome versions. But I’m finding it very limited in “functional” programming, because it lacks classic map, filter etc. methods that would work nicely with a [key, val…

How do you properly return multiple values from a Promise?

I’ve recently run into a certain situation a couple of times, which I didn’t know how to solve properly. Assume the following code: Now a situation might arise where I would want to have access to amazingData in afterSomethingElse. One obvious solution would be to return an array or a hash from af…

How to get a number value from an input field?

I have some issues with calculating some stuff with JS and getting the right values out of the input fields (number). When I use this code it doesn’t show anything. So what is wrong with my JS? Do I need to include a jQuery file? Answer You had some mistakes in your HTML, but here is a working JSFiddle:…