React developer

Ninja is playing with numbers but hates when he gets duplicate numbers. Ninja is provided an array, and he wants to remove all duplicate elements and return the array, but he has to maintain the order in which the elements were supplied to him.

They asked me a React coding question where I had to implement a traffic light system. I had to display red, yellow, and green lights that changed automatically after a specific interval using state and hooks.

Explain the Event loop. (Learn)

const obj = { a: 1 };
const map = new Map();
map.set(obj, "value");
obj = null;
console.log(map.keys().next().value);

console.log([] + []);
console.log([] + {});
console.log({} + []);

Explain hoisting, let, var, and const. (Learn)

Explain the difference between React.memo and the memo hook.

Explain, as a team lead, how you set up a repository on GitHub and what best practices you follow.