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Clarify inference example #3387

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Clarify inference example #3387

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Clarify type inference behavior in 'Push Type Parameters Down' example
yoKurt94 May 15, 2025
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Clarify type inference behavior in 'Push Type Parameters Down' section
yoKurt94 May 15, 2025
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3 changes: 2 additions & 1 deletion packages/documentation/copy/en/handbook-v2/More on Functions.md
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Expand Up @@ -292,7 +292,8 @@ const b = firstElement2([1, 2, 3]);
```

These might seem identical at first glance, but `firstElement1` is a much better way to write this function.
Its inferred return type is `Type`, but `firstElement2`'s inferred return type is `any` because TypeScript has to resolve the `arr[0]` expression using the constraint type, rather than "waiting" to resolve the element during a call.
Its inferred return type is `Type`, but `firstElement2`'s inferred return type is `any` because TypeScript uses the constraint type `any[]`, rather than `Type`, when resolving the `arr[0]` expression.


> **Rule**: When possible, use the type parameter itself rather than constraining it

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