I'm working with a Map in JavaScript and need to check that it doesn't contain duplicate keys. The map I'm working with is below. const colors = new Map([ [1, 'blue'], [2, 'orange'], [1, 'pink'], // This duplicate key should…
I am foraying back into the world of web development, so there is a good chance that this is something silly I have overlooked. I have been able to dynamically create all the HTML components for the SVG I am…
I am creating a canvas based tool using FabricJS within a React App. I am using the latest NPM Package 6.4.3 and I am struggling to add an image to the canvas. Very recently they have switched to TypeScript and…
node: 20.15.1 jest: 29.7.0 jest-environment-jsdom: 29.7.0 const response = await fetch(url, { signal: AbortSignal.timeout(5000) }); I want to unit test the above line of javascript using Jest. Specifically the timeout behaviour. But is that actually possible? No matter what I…
I have a json objects containing dynamic properties and want to export it to excel(using javascript) such that excel recognizes date string(2020-03-13) as date object(I don't know type of any json key, so I can't use type neither format, date…
CSB link: https://codesandbox.io/p/sandbox/74mhkd Observation I create two similar inputs in the sandbox. The first one is the most common, and it works as expected. const [value1, setValue1] = useState("first"); <input value={value1} onChange={(e) => { setValue1(e.target.value); }} /> Then, for the…
im tring to call this hook but im receiving this error Possible Unhandled Promise Rejection (id: 6): Error: Invalid hook call. Hooks can only be called inside of the body of a function component. this is my code: const handleEvento…
I'm working on creating a pixel-based light in the dark simulation with JavaScript to improve my coding skills. The goal is to create a bubble of light around the cursor as it moves. I'm only rendering a small portion around…
Consider following code snippet: <script> let a=1; console.log(a); //prints 1 </script> <script> console.log(a); //prints 1 </script> I want to ask if a is block scoped due to the declaration by let which means it is scoped to single <script> tag…
I have a little problem to add some element in place into an array. I'm trying to add after the last lowercase letter that is z the uppercase letter of the alphabet. I'm using this code. I've noticed that the…