30 Asked Interview Questions and Answers (2024)

The 'map' function is used to transform each element of an array and create a new array with the results.

Example:

const numbers = [1, 2, 3]; const doubled = numbers.map(num => num * 2);

The 'filter' function is used to create a new array with elements that satisfy a given condition.

Example:

const numbers = [1, 2, 3, 4, 5]; const evens = numbers.filter(num => num % 2 === 0);

The 'reduce' function is used to accumulate the elements of an array into a single value.

Example:

const numbers = [1, 2, 3, 4, 5]; const sum = numbers.reduce((acc, num) => acc + num, 0);

The 'find' function is used to find the first element in an array that satisfies a given condition.

Example:

const numbers = [1, 2, 3, 4, 5]; const result = numbers.find(num => num > 2);

Rest parameters allow a function to accept an indefinite number of arguments as an array.

Example:

function sum(...numbers) { return numbers.reduce((acc, num) => acc + num, 0); }

ES6 Interview Questions and Answers