30 Asked Interview Questions and Answers (2024)

Default parameter values allow you to specify default values for function parameters if no value or undefined is passed.

Example:

function greet(name = 'Guest') { console.log(`Hello, ${name}!`); }

Object.assign() is used to copy the values of all enumerable own properties from one or more source objects to a target object.

Example:

const target = {}; const source = { a: 1, b: 2 }; Object.assign(target, source);

Array.from() is used to create a new shallow-copied array from an array-like or iterable object.

Example:

const arrayLike = { 0: 'a', 1: 'b', length: 2 }; const newArray = Array.from(arrayLike);

Array.of() is used to create a new array with a variable number of arguments, regardless of their types.

Example:

const newArray = Array.of(1, 'hello', true);

Array.findIndex() is used to find the index of the first element in an array that satisfies a given condition.

Example:

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

ES6 Interview Questions and Answers