### Define ```ts interface Dictionary<T> { [key: string]: T; } ``` ### Usage ```ts let v1: Dictionary<number>; let v2: Dictionary<string>; let v3: Dictionary<any>; ``` This is a very common and useful definition, also mentioned in the [official documentation.](http://www.typescriptlang.org/docs/handbook/advanced-types.html )
Define
Usage
This is a very common and useful definition, also mentioned in the official documentation.