1# Use unique names for types and namespaces. 2 3Rule ``arkts-unique-names`` 4 5**Severity: error** 6 7Names for all types (classes, interfaces, enums) and namespaces must be unique 8and distinct from other names, e.g., variable names and function names. 9 10 11## TypeScript 12 13 14``` 15 16 let X: string 17 type X = number[] // Type alias with the same name as the variable 18 19``` 20 21## ArkTS 22 23 24``` 25 26 let X: string 27 type T = number[] // X is not allowed here to avoid name collisions 28 29``` 30 31 32