## Problem Implement the following JavaScript utility functions without using the built-in equivalents: **Part 1:** Implement `myReduce(arr, fn, initialValue)` matching the behavior of `Array.prototype.reduce`. **Part 2:** Implement `myPromiseAll(promises)` matching `Promise.all` - resolves when all resolve, rejects on first rejection. **Part 3:** Implement `myFlatten(arr, depth)` matching `Array.prototype.flat(depth)`. ```js // Part 1 myReduce([1,2,3,4], (acc, x) => acc + x, 0) // -> 10 // Part 2 myPromiseAll([Promise.resolve(1), Promise.resolve(2)]).then(vs => console.log(vs)) // -> [1, 2] // Part 3 myFlatten([1,[2,[3,[4]]]],2) // -> [1, 2, 3, [4]] ``` ## Follow-ups 1. How would you implement `myPromiseAllSettled` that never rejects? 2. What happens in your `myReduce` if no `initialValue` is provided? 3. Implement `myPromiseRace` - resolves or rejects with the first settled promise. 4. How would you implement lazy evaluation using generators instead of `reduce`?

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JavaScript Methods - Implement Array and Promise Utilities from Scratch

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Problem Implement the following JavaScript utility functions without using the built-in equivalents: Part 1: Implement myReduce(arr, fn, initialValue) matching the behavior of Array.prototype.reduce. Part 2: Implement myPromiseAll(promises) matching Promise.all - resolves when all resolve, rejects on first rejection. Part 3: Implement myFlatten(arr, depth) matching Array.prototype.flat(depth). Follow-ups How would you implement myPromiseAllSettled that never rejects? What happens in your myReduc…

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This is a candidate experience report from a c3 ai interview during the phone round.

It covers the following topics: Arrays, Coding, Phone, Frontend .

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JavaScript Methods - Implement Array and Promise Utilities from Scratch

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