Product mockup

NaN !== NaN; Developer T-Shirt (JavaScript Edition — Dark Mode)

XS
£25.00
Sale price  £25.00 Regular price 
Skip to product information
Product mockup
1/7

NaN !== NaN; Developer T-Shirt (JavaScript Edition — Dark Mode)

£25.00
Sale price  £25.00 Regular price 
Size

A clean, clever nod to one of JavaScript's most iconic quirks. This Dark Mode tee features the paradox we've all debugged at least once:

NaN !== NaN;

It's subtle enough for everyday wear, but instantly recognisable to anyone who's wrestled with type coercion, floating-point shenanigans, or mysterious “why isn't this equal?” moments.

Soft, durable, and perfect for deep-focus coding, remote work sessions, or quietly laughing at the language you love (and occasionally fear).

  • 100% combed and ring-spun cotton (Heather colors contain polyester)
  • Fabric weight: 4.2 oz./yd.² (142 g/m²)
  • Pre-shrunk fabric
  • Side-seamed construction
  • Shoulder-to-shoulder taping
  • Blank product sourced from Nicaragua, Mexico, Honduras, or the US

Disclaimer: The fabric is slightly sheer and may appear subtly see-through under certain lighting conditions.

Printed on demand — predictable comfort, unpredictable comparisons.

Part of the JavaScript collection, within Web & Frontend.

Available in Dark Mode and Light Mode.

Review our T-Shirt size guide

Heads-up

Shipping costs vary by region, so it’s worth giving the delivery total at checkout a quick look before confirming your order. Some variants may show limited availability in certain locations—if fulfilment isn’t available in your region, our suppliers will try to ship globally from the nearest facility that can produce that specific item. When this happens, delivery costs may be higher than expected due to the increased distance.

We’re constantly reviewing suppliers and expanding fulfilment options, and new routes may open over time.

If you’d like updates when things change, you can join our mailing list at the bottom of the page.

EU Product Safety (GPSR) Compliance

Discover why NaN !== NaN in JavaScript. Learn about NaN behavior, proper ways to check for NaN, and the difference between isNaN() and Number.isNaN().

Discover why NaN !== NaN in JavaScript. Learn about NaN behavior, proper ways to check for NaN, and the difference between isNaN() and Number.isNaN().

NaN (Not-a-Number) is JavaScript's representation of undefined numeric results. The quirk: NaN doesn't equal itself. NaN !== NaN returns true, violating the expectation that values equal themselves. Understanding NaN behavior prevents bugs in numeric code.

Read the article

You may also like