Sample question for test fundamental knowledge of JS

gistfile1.txt

export {};

function findClosestNumber(arr: number[], target: number): number {
    // Sort the array in ascending order
    arr.sort((a, b) => a - b);

	let closest: number = arr[0];
	let minDifference: number = Math.abs(target - closest);

	arr.forEach((num) => {
		const difference: number = Math.abs(target - num);
		if (difference < minDifference) {
			minDifference = difference;
			closest = num;
		}
	});

	return closest;
}

// Example usage:
let arr: number[] = [2, 5, 6, 7, 8, 8, 9];
let target = 4;
let result: number = findClosestNumber(arr, target);
console.log(`Closest number to ${target} is ${result}`);

gistfile2.txt

export {};

function closestNumbers(arr: number[]): number[] {
	// Sort the array
	arr.sort((a, b) => a - b);

	let minDiff = Number.MAX_SAFE_INTEGER;
	let result: number[] = [];

	// Calculate the minimum absolute difference
	for (let i = 1; i < arr.length; i++) {
		const diff = Math.abs(arr[i] - arr[i - 1]);
		if (diff < minDiff) {
			minDiff = diff;
			result = [arr[i - 1], arr[i]];
		} else if (diff === minDiff) {
			result.push(arr[i - 1], arr[i]);
		}
	}

	return result;

}

let array = [-20, -3916237, -357920, -3620601, 7374819, -7330761, 30, 6246457, -6461594, 266854, -520, -470];
let result = closestNumbers(array);
console.log(result.join(' ')); // Output: "-520 -470 -20 30"

gistfile3.txt

export {}

// map
const numbers = [1, 2, 3, 4];
const doubled = numbers.map((item,index,number) => item * 2);
console.log(doubled); // [2, 4, 6, 8]

// filter
const students = [
  { name: 'Quincy', grade: 96 },
  { name: 'Jason', grade: 84 },
  { name: 'Alexis', grade: 100 },
  { name: 'Sam', grade: 65 },
  { name: 'Katie', grade: 90 }
];

const studentGrades = students.filter(student => student.grade >= 90);
console.log('My object: ', studentGrades); // [ { name: 'Quincy', grade: 96 }, { name: 'Alexis', grade: 100 }, { name: 'Katie', grade: 90 } ]

// reduce
const numbers_reduce = [1, 2, 3, 4];
const sum = numbers_reduce.reduce(function (result, item) {
  return result + item;
}, 0);
console.log(sum); // 10

gistfile4.txt

export {};

function cutTheSticks(arr: number[]): number[] {
    const result: number[] = [];
    // Sort the array in ascending order
    arr.sort((a, b) => a - b);
    
    // While there are sticks remaining
    while (arr.length > 0) {
        // Print the number of sticks remaining
        result.push(arr.length);
        
        // Find the length of the shortest stick
        const shortest = arr[0];
        
        // Cut all sticks to the length of the shortest stick
        arr = arr.map(stick => stick - shortest).filter(stick => stick > 0);
    }
    
    return result;
}

// Example usage:
const sticks = [5, 4, 4, 2, 2, 8];
const result = cutTheSticks(sticks);
console.log(result); // Output: [6, 4, 2, 1]