console.log(foo); var foo = 1; console.log(foo); let foo = 2; console.log(foo); const foo = 3; console.log(foo);
Middle
140
Frontend
6413
681
Have you had experience working with Legacy code?
Middle
139
Imagine a situation where performance drops due to a problem in JS code. What would you check in DevTools profiler to confirm or deny this hypothesis?
Middle
138
A array of 2 million elements arrives, each element needs to be processed for 100 milliseconds. Interaction with the server cannot be changed. How to process this array so as not to block the UI?
Middle
138
How do you feel about criticism during code review?
Middle
138
Please clarify: was the move from JS/JSVue to React and TypeScript, and is there a plan to move to micro frontends?
Middle
137
In the requestUserData function, three requests are executed sequentially. Why can't all three be wrapped in Promise.all? How to optimize this function to perform requests in the shortest time?
Middle
135
What is SSR (Server-Side Rendering)? Why use it and what should be considered when translating an application to SSR?
Middle
133
Why is it not recommended to store sensitive data in localStorage?
Middle
131
Have you had experience writing tests?
Middle
128
let a = 5; setTimeout(function timeout() { //macro console.log(a); a = 10; }, 0); let p = Promise.resolve().then(data => { console.log(a); a = 25; resolve(); }).then() console.log(a); // 5 25 25
Middle
128
Why shouldn't you make each component of an application a separate chunk via React.lazy? What problems could this create (with rendering, network, bundle size)?
Middle
123
There is a React application built into a single chunk. How to split it into several chunks and on what principle?
Middle
121
Tell us about the Event Loop in JavaScript.
Middle
114