for-in statement
typescript
Solution
The for-in statement is really there to enumerate over object properties, which is how it is implemented in TypeScript. There are some issues with using it on arrays.
I can't speak on behalf of the TypeScript team, but I believe this is the reason for the implementation in the language.
Problem
TypeScript docs say nothing about loop like `for` or `for-in`. From playing with the language it seems that only `any` or `string` variables are supported in `for` loop. Why has this decision been made? Why not use the type information and have strongly-typed iteration variable?