JavaScript interview questions and answers

ReactNode covers strings, numbers, fragments, and elements, which is what most layout components accept.

It is the work from HTML and CSS bytes to pixels: parse, CSSOM, render tree, layout, paint.

Leading runs immediately, then ignores calls until the window ends

As const on a route name array makes a union of literal strings instead of string.

I take heap snapshots before and after visiting a route twice and look for detached DOM nodes or growing arrays.

JavaScript runs on one call stack.

Destructuring pulls values from arrays or objects into named variables in one line.

Spread copies array or object properties into a new literal.

It is the browser steps from HTML and CSS to first painted pixels: parse DOM, parse CSSOM, render tree, layout, paint.

Promise callbacks are microtasks and run before the next macrotask like setTimeout.