Engineer bro!
Wed Mar 16 2022 (2 years ago)
Engineer by mistake!
I am a software engineer by passion
In this article, I have listed 25 javascript MCQs for you to practice. Comment your answer with proper justification.
Q15 - With which constructor can we successfully extend the Dog class?
Q20 - How can we log the values that are commented out after the console.log statement?
function Car() {
this.make = 'Lamborghini';
return { make: 'Maserati' };
}
const myCar = new Car();
console.log(myCar.make);
(() => {
let x = (y = 10);
})();
console.log(typeof x);
console.log(typeof y);
class Dog {
constructor(name) {
this.name = name;
}
}
Dog.prototype.bark = function() {
console.log(`Woof I am ${this.name}`);
};
const pet = new Dog('Mara');
pet.bark();
delete Dog.prototype.bark;
pet.bark();
const set = new Set([1, 1, 2, 3, 4]);
console.log(set);
// counter.js
let counter = 10;
export default counter;
// index.js
import myCounter from './counter';
myCounter += 1;
console.log(myCounter);
const name = 'Lydia';
age = 21;
console.log(delete name);
console.log(delete age);
const numbers = [1, 2, 3, 4, 5];
const [y] = numbers;
console.log(y);
const user = { name: 'Lydia', age: 21 };
const admin = { admin: true, ...user };
console.log(admin);
const person = { name: 'Lydia' };
Object.defineProperty(person, 'age', { value: 21 });
console.log(person);
console.log(Object.keys(person));
const settings = {
username: 'lydiahallie',
level: 19,
health: 90,
};
const data = JSON.stringify(settings, ['level', 'health']);
console.log(data);
let num = 10;
const increaseNumber = () => num++;
const increasePassedNumber = number => number++;
const num1 = increaseNumber();
const num2 = increasePassedNumber(num1);
console.log(num1);
console.log(num2);
const value = { number: 10 };
const multiply = (x = { ...value }) => {
console.log((x.number *= 2));
};
multiply();
multiply();
multiply(value);
multiply(value);
[1, 2, 3, 4].reduce((x, y) => console.log(x, y));
class Dog {
constructor(name) {
this.name = name;
}
};
class Labrador extends Dog {
// 1
constructor(name, size) {
this.size = size;
}
// 2
constructor(name, size) {
super(name);
this.size = size;
}
// 3
constructor(size) {
super(name);
this.size = size;
}
// 4
constructor(name, size) {
this.name = name;
this.size = size;
}
};
// index.js
console.log('running index.js');
import { sum } from './sum.js';
console.log(sum(1, 2));
// sum.js
console.log('running sum.js');
export const sum = (a, b) => a + b;
console.log(Number(2) === Number(2));
console.log(Boolean(false) === Boolean(false));
console.log(Symbol('foo') === Symbol('foo'));
const name = 'Lydia Hallie';
console.log(name.padStart(13));
console.log(name.padStart(2));
console.log('🥑' + '💻');
function* startGame() {
const answer = yield 'Do you love JavaScript?';
if (answer !== 'Yes') {
return "Oh wow... Guess we're gone here";
}
return 'JavaScript loves you back ❤️';
}
const game = startGame();
console.log(/* 1 */); // Do you love JavaScript?
console.log(/* 2 */); // JavaScript loves you back ❤️
console.log(String.raw`Hello\nworld`);
async function getData() {
return await Promise.resolve('I made it!');
}
const data = getData();
console.log(data);
function addToList(item, list) {
return list.push(item);
}
const result = addToList('apple', ['banana']);
console.log(result);
const box = { x: 10, y: 20 };
Object.freeze(box);
const shape = box;
shape.x = 100;
console.log(shape);
const { name: myName } = { name: 'Lydia' };
console.log(name);
© 2021 dsabyte. All rights reserved