It looks like a timing bug in setTimeout. It isn't. It's var's scope rules doing exactly what they're designed to do — and the fix is one keyword, once you know why.
It looks like a timing bug in setTimeout. It isn't. It's var's scope rules doing exactly what they're designed to do — and the fix is one keyword, once you know why.
Adapted from the JavaScript Essentials Companion Guide.
You write a loop that should print 0, 1, and 2, one second apart. Instead you get three 3s.
for (var i = 0; i < 3; i++) {
setTimeout(() => console.log(i), 1000);
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