JavaScript

optional chaining in JavaScript

JavaScriptOperatorsoptional chainingbeginner

What this snippet does

?. short-circuits to undefined instead of throwing when a property doesn't exist on null or undefined.

Expected output

undefined
undefined
undefined
undefined

Why practise typing this

Typing operators 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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