JavaScript

Result type in JavaScript

JavaScriptError HandlingResult type patternadvanced

What this snippet does

The Result pattern makes errors visible in return types — callers are forced to handle both cases instead of forgetting try/catch.

Expected output

value: 5
error: Division by zero
value: 42
error: Not a number: abc

Why practise typing this

Typing error handling 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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