强制Typescript对象的索引成员的类型？

Question

我希望在Typescript对象中存储String->string的映射，并强制所有键映射到字符串。例如：

var stuff = {};
stuff["a"] = "foo";   // okay
stuff["b"] = "bar";   // okay
stuff["c"] = false;   // ERROR!  bool != string

我有办法强制要求值必须是字符串（或任何类型..）吗？

Answer 1

var stuff: { [key: string]: string; } = {};
stuff['a'] = ''; // ok
stuff['a'] = 4;  // error

// ... or, if you're using this a lot and don't want to type so much ...
interface StringMap { [key: string]: string; }
var stuff2: StringMap = { };
// same as above