Why does [10, 9, 1].sort() return [1, 10, 9] in JavaScript?

Question

What does this log?

console.log([10, 9, 1].sort());

Accepted Answer

[1, 10, 9] — Array.prototype.sort() coerces elements to strings and compares them lexicographically unless you pass a comparator. "10" sorts before "9" because "1" < "9". Always pass (a, b) => a - b for numbers.

Why does [10, 9, 1].sort() return [1, 10, 9] in JavaScript?#

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Why does [10, 9, 1].sort() return [1, 10, 9] in JavaScript?