What this snippet does
The cache object lives in the closure — subsequent calls with the same args skip the computation entirely.
Expected output
computing... 25 cache hit 25 computing... 36
Why practise typing this
Typing closures code builds muscle memory for the symbols and indentation JavaScript uses most, which prose-based typing tests never cover. DevType measures your words per minute and accuracy on this snippet and tracks the individual characters you mistype, so later lessons can target them.
More JavaScript practice
- closure basicsClosures · intermediate
- closure counterClosures · intermediate
- var loop bindingClosures · intermediate
- closure factoryClosures · intermediate
- partial applicationClosures · intermediate
- private closureClosures · intermediate