What this snippet does
Without a comparator, sort() converts to strings — '10' < '2' alphabetically, so always pass (a, b) => a - b for numbers.
Expected output
[ 10, 2, 20, 30, 4 ] [ 2, 4, 10, 20, 30 ] [ 30, 20, 10, 4, 2 ]
Why practise typing this
Typing arrays 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.
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