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Math.sign: How to Check if a Number is Positive or Negative in JavaScript

Samantha Ming on April 07, 2020

Determining the sign of a number is super easy now with ES6's Math.sign 👏 It will indicate whether the number is positive, negative or zero. co...

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Davyd McColl • Apr 8 '20 • Edited

slight error:

Math.sign either returns 1 or -1, so:

if (Math.sign(number)) {
  // always run
} else {
  // never run
}

did you perhaps mean if (Math.sign(number) > 0) ? in which case if (number > 0) is more concise.

Samantha Ming • Apr 9 '20

OH good catch, let me fix it! Thanks for letting me know 😱

Dharan • Apr 7 '20

Its crazy to know, that even a positive / negative one line execution needs this much knowledge LoL

Samantha Ming • Apr 7 '20

hahahaha 😂Tip of the iceberg...always more to know and more to learn when it comes to javascript 😆

jonyx • Apr 8 '20

Gotcha!

Samantha Ming • Apr 9 '20

Laugh with sadness -- a perfect description of IE 😵

Lara Durrant • Apr 8 '20

Thanks for the article! It’s always a good reminder that there’s probably a built in JavaScript method for pretty much anything you wanna do! :)

Samantha Ming • Apr 9 '20

Totally! JS is a big toolbox and continues to add more tools for us to use, which is awesome. Thanks for reading my article 👏

Aral Roca • Apr 8 '20

+10 years with JavaScript and I never listen about negative 0! But make sense...

Samantha Ming • Apr 9 '20

I only learned the negative 0 when i wrote this article. It will be interesting to see when i can actually apply it. I'll make sure to share when that happens 😊

hafizpustice05 • Apr 7 '20

Great content.

Samantha Ming • Apr 7 '20

Thanks! Glad you liked the article 😄

Benny Powers 🇮🇱🇨🇦 • Apr 7 '20

Love your posts, Samantha, keep them coming

Samantha Ming • Apr 7 '20

you bet! thanks for the encouragement benny 😊

Başar Özcan • Apr 7 '20

you always find a good topic, thank you

Samantha Ming • Apr 7 '20 • Edited

thank you! i just pick topics that i want to learn, luckily this one resonates with you 😄And if there is a topic you want me to cover, please let me know! 👏