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7 Javascript Tips and Tricks

Ega Prasetya on September 26, 2020

Filter Unique Values The Set object type was introduced in ES6, and along with (...), the spread operator, we can use it to create a new...

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Mišo • Sep 26 '20

Hi, while the conversion hacks are interesting, PLEASE note in bold (as with Math.*) that proper readable methods should be used. It's really cryptic in the real life code to decode these tricks because people think this is the only and proper way instead of these:

const isFalse = Boolean(0);
const numeric = String(29);
const integer = Number("36");  // or better parseInt("36", 10)

Ega Prasetya • Sep 26 '20

nice corrections, thank you.

Jon Randy 🎖️ • Sep 27 '20

Beware - truncating an integer and using any of Math.floor, Math.ceil, and Math.round are NOT the same thing:

console.log(-23.9 | 0); // Result: -23
console.log(Math.floor(-23.9)); // Result -24
console.log(Math.ceil(-23.9)); // Result -23
console.log(Math.round(-23.9)); // Result -24

console.log(23.9 | 0); // Result: 23
console.log(Math.floor(23.9)); // Result 23
console.log(Math.ceil(23.9)); // Result 24
console.log(Math.round(23.9)); // Result 24