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{|x| x _ x} Developer T-Shirt

Black Heather / XS
£25.00
Sale price  £25.00 Regular price 
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{|x| x _ x} Developer T-Shirt

{|x| x * x} is a Ruby block: the |x| names the parameter, and the body squares it. Hand it to a method like map and it runs once per element — [1,2,3].map { |x| x * x } gives [1,4,9]. The anonymous function Ruby threads through nearly everything it does, written inline at the point you need it.

£25.00
Sale price  £25.00 Regular price 
Mode: Dark Mode (Black Heather)
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100% cotton
Made to order
Dark + Light
Technical details
  • 100% combed and ring-spun cotton (Heather colours 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

The fabric is slightly sheer and may appear see-through, particularly in lighter colours or bright lighting.

Printed on demand — each piece is made to order.

Care
  • Machine wash cold, inside out, with like colours
  • Tumble dry low, or hang to dry
  • Do not iron directly on the print
  • Do not bleach or dry clean
Shipping and returns

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.

EU Product Safety (GPSR) Compliance

Part of the Ruby collection, within Backend & Server.

Available in Dark Mode and Light Mode.

Ruby Blocks Explained: Understanding {|x| x * x} Syntax

Ruby Blocks Explained: Understanding {|x| x * x} Syntax

Blocks are fundamental to Ruby. The {|x| x * x} syntax defines anonymous functions you pass to methods. Understanding blocks, procs, and lambdas—and when to use each—is central to writing idiomatic Ruby.

Read the article

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