Typescripts goal is to allow using existing JavaScript idioms while gaining the advantages of static type checking. I don't think it's too bonkers for the type

Typescripts goal is to allow using existing JavaScript idioms while gaining the advantages of static type checking. I don't think it's too bonkers for the type of a variable to change within the same scope, as long as there's some clear delineation. In rust you can redeclare a variable with the same name but different type: let x: i32 = 99; println!("{}", x); let x: &str = "shadows"; println!("{}", x); Kotlin does something very similar to typescript for null checks: https://kotlinlang.org/docs/reference/null-safety.html https://kotlinlang.org/docs/reference/null-safety.html I don't know what's so crazy about a variable's type changing within the same scope except that languages from before 2010 mostly didn't allow that.