### Frontend Screening Interview Questions

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#### Q. How do you check if a variable holds an array?
###### A. Using `Array.isArray` function.

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#### Q. How would you generate a long string of a single character?
###### A. Using `String.repeat` function. Example, `'M'.repeat(255);` will generate 255 `M` characters in a single string

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#### Q. Is `Promise` constructor `async` like `setTimeout` or `sync`?
###### A. It is `sync`.

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#### Q. What is the difference between `Function.call` and `Function.bind`?
###### A. `Function.bind` returns a new function with bounded arguments, while `Function.call` just calls the function with the given arguments.

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#### Q. What is the difference between `Function.reduce` and `Function.map`?
###### A. `Function.reduce` acts like a collection aggregator while `Function.map` just returns a new array probably after performing some calculation on the original array's elements.

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#### Q. When would you opt for using `Map` instead of a simple `object`?
###### A. If we have constantly changing object then we would use `Map` for its high performance, while for static objects a simple `object` would work.

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#### Q.When do `useMemo` and `useEffect` run in a component life cycle?
###### A. `useMemo` runs before a component renders while `useEffect` runs after component has rendered and is mounted in the browser DOM.

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#### Q. Would you choose React `Context` to store the application data or a state manager?
###### A. Use a state manager always, `Context` is used only for light weighted information sharing.

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#### Q. What are the advantages of `CSS-in-JS` and `CSS Modules` over the standard CSS in React?
###### A. These solutions scope the CSS thus a developer is free to use same CSS rule name across the project without having a name collision and rules overriding.