JSON limits in JavaScript

What this snippet does

JSON only handles strings, numbers, booleans, null, arrays, and plain objects — functions, undefined, and Symbols are silently dropped.

Expected output

{"name":"Alice","age":30}
undefined
null
null

Why practise typing this

Typing json 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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