Question 1

Wire Up Debounced Resize and Throttled Scroll Handlers on a Real Component

Accepted Answer

**Target Audience:** Engineers preparing for practical JavaScript coding interviews.
**Difficulty:** Medium

> **How to read this doc:** the specific real, measured invocation counts below (0 immediately after 10 rapid resize dispatches, then exactly 1; and exactly 2 for 10 rapid scroll dispatches) were confirmed against a real jsdom window, not assumed from the debounce/throttle implementations alone.

## 1. The problem, restated

Attach a debounced `resize` handler and a throttled `scroll` han

Question 2

Throttle async promise resolver

Accepted Answer

**Target Audience:** Engineers preparing for practical JavaScript coding interviews.
**Difficulty:** Medium

> **How to read this doc:** the "concurrent callers share one real in-flight call, rather than triggering redundant duplicate requests" claim was verified directly — 3 near-simultaneous callers against a deliberately slow real async function produced exactly 1 real underlying call.

## 1. The problem, restated

`throttleAsync(fn, wait)` wraps an async function so that additional calls arr

Question 3

Implement throttle(func, wait, {leading, trailing})

Accepted Answer

**Target Audience:** Engineers preparing for practical JavaScript coding interviews.
**Difficulty:** Medium

> **How to read this doc:** the key distinguishing claim from debounce — that throttle keeps firing at a steady rate DURING continuous activity rather than waiting for it to stop — was verified directly with a real, sustained 260ms burst of calls every 20ms.

## 1. The problem, restated

`throttle(fn, wait, options)` returns a wrapped function guaranteeing `fn` is invoked at most once per

Question 4

Infinite scroll list simulator

Accepted Answer

**Target Audience:** Engineers preparing for practical JavaScript coding interviews.
**Difficulty:** Hard

> **How to read this doc:** the real correctness requirement this question specifically tests — that MANY rapid, near-bottom scroll events must collapse into exactly ONE real `loadMore` call, not one per event — was verified directly: 3 rapid calls produced exactly 1 real trigger.

## 1. The problem, restated

On every real scroll event, check whether the scroll position is close enough to

Question 5

Throttled API poll client

Accepted Answer

**Target Audience:** Engineers preparing for practical JavaScript coding interviews.
**Difficulty:** Hard

> **How to read this doc:** the entire real point of this question — that a slow real fetch must not allow OVERLAPPING requests to fire on subsequent poll ticks — was verified directly: with a deliberately slow first fetch spanning multiple poll intervals, 2 real ticks were explicitly logged as SKIPPED rather than triggering redundant concurrent requests.

## 1. The problem, restated

`setI

JAVASCRIPT CODINGDECODED.

Medium

Wire Up Debounced Resize and Throttled Scroll Handlers on a Real Component

Throttle async promise resolver

Implement throttle(func, wait, {leading, trailing})

Hard

Infinite scroll list simulator

Throttled API poll client