DEV Community

Alfredo Salzillo
Alfredo Salzillo

Posted on

Can you hack this? #1

#javascript #fun #challenge

Say that we have a function called nameEqualsToItself how accept a person object as input that checks if the name property of the input object equal the same name property of the input object implemented like this:

const nameEqualsToItself = (person) => person.name === person.name
Enter fullscreen mode Exit fullscreen mode

Can you find the input that makes nameEqualsToItself return false?

const personX = ???
console.log(nameEqualsToItself(personX)) // print `false`
Enter fullscreen mode Exit fullscreen mode

Top comments (12)

Collapse
 
afif profile image
Temani Afif • • Edited 
const personX={};
personX.name=NaN;
Enter fullscreen mode Exit fullscreen mode

OR simply

const personX={name:NaN};
Enter fullscreen mode Exit fullscreen mode

a. If x or y are any of NaN, +∞𝔽, or -∞𝔽, return false. ref

Collapse
 
akashkava profile image
Akash Kava •

It will return false only for NaN, because Number.POSITIVE_INFINITY === Number.POSITIVE_INFINITY returns true, and it is same for negative infinity as well.

Collapse
 
alfredosalzillo profile image
Alfredo Salzillo •

Also if using a Getter or a Proxy returning different values each time :)

Thread Thread
 
atulcodex profile image
🚩 Atul Prajapati 🇮🇳 •

You don't know everything 😛

Collapse
 
kinzmak profile image
Kins • • Edited 
const personX = { get name() { return Math.random() } };
console.log(nameEqualsToItself(personX)); //This will return false as well
Enter fullscreen mode Exit fullscreen mode
Collapse
 
shane profile image
Shane McGowan • • Edited

This is big brain, love it

Collapse
 
aminnairi profile image
Amin •

Using a Proxy.

"use strict";

const personNameEqualsItself = person => person.name === person.name;

const person = (() => {
  let boolean = true;

  return new Proxy({}, {get: (target, property) => property === "name" ? boolean = !boolean : undefined});
})();

console.log(personNameEqualsItself(person)); // false
console.log(personNameEqualsItself(person)); // false
console.log(personNameEqualsItself(person)); // false
Enter fullscreen mode Exit fullscreen mode
Collapse
 
rkichenama profile image
Richard Kichenama • 
const personX = new Proxy({}, { get (target, attr) { return /name/i.test(attr) ? Symbol('name') : target[attr]; });
Enter fullscreen mode Exit fullscreen mode
Collapse
 
Sloan, the sloth mascot
Comment deleted
Collapse
 
alfredosalzillo profile image
Alfredo Salzillo •

It print true :) try it

Collapse
 
ironcladdev profile image
Conner Ow •

It printed false.

const nameEqualsToItself = (person) => person.name === person.name
const personX = { name: NaN, };
console.log(nameEqualsToItself(personX))
Enter fullscreen mode Exit fullscreen mode
View full discussion (12 comments)

Some comments may only be visible to logged-in visitors. Sign in to view all comments.

Read next

teo_nordic_d6988ee4c1221e profile image

Exploring Java's Role in Cloud Computing and AI for 2024

Teo Nordic -

guillaumesere profile image

Créer une Radio en Ligne avec l'API Radio Browser

Guillaume Sere -

aralroca profile image

Brisa Framework Presentation - October 2024

Aral Roca -

estifanos_ameha_e94b23bd2 profile image

Express or NestJS? Choosing the Best Framework for Your Backend

Estifanos Ameha -