JavaScript

nullish coalescing in JavaScript

JavaScriptOperatorsnullish coalescingbeginner

What this snippet does

?? differs from || by only treating null and undefined as missing — 0, '', and false are valid values.

Expected output

default
default
0

false

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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