for...in arrays in JavaScript

What this snippet does

for...in on an array gives string index keys not values — use for...of for arrays to avoid this trap.

Expected output

string 0
string 1
string 2
string a
string b
string c

Why practise typing this

Typing loops 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

• for loopLoops · beginner
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• for...in loopLoops · beginner
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