What this snippet does
The set trap runs on every property write — perfect for building type-safe or validated data objects without a class.
Expected output
Alice 30 age must be number
Why practise typing this
Typing proxy 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
- proxy getProxy · advanced
- proxy loggingProxy · advanced
- proxy schemaProxy · advanced
- let vs constVariables · beginner
- const configVariables · beginner
- const mutationVariables · beginner