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Discussion on: 17 Javascript optimization tips to know in 2021 🚀

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denisdiachenko profile image
DenisDiachenko •

That's a good list, just one thing I would like to mention in tips 4 and 5. It's better to check if the value is null or undefined using Nullish Coalescing Operator (??) since for some cases it might be an unexpected behavior:

const foo = null || 42;
console.log(foo);
// expected output: 42
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const foo = 0 || 42;
console.log(foo);
// expected output: 0, but will be 42
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So, in that case ?? will work as expected

const baz = 0 ?? 42;
console.log(baz);
// expected output: 0 and will be 0
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Thank you for your work!

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blessinghirwa profile image
Blessing Hirwa •

In some cases Nullish Coalescing Operator is the best choice. Thanks for the assistance.