用DRY将对象文字转换为类型

只做:

const myObject = {
   hello: 'how are you',
   hey: 'i am fine thank you'
}

type myObjectType = keyof typeof MyObject

完成工作!

如果你试图写一个类型注释，语法是:

var x: { property: string; } = { property: 'hello' };

如果你试图写一个对象文字，语法是:

var x = { property: 'hello' };

您的代码试图在值位置使用类型名称。

我很惊讶没有人提到这一点，但你可以创建一个名为ObjectLiteral的接口，它接受类型string: any的键:值对:

interface ObjectLiteral {
  [key: string]: any;
}

然后你可以这样使用它:

let data: ObjectLiteral = {
  hello: "world",
  goodbye: 1,
  // ...
};

一个额外的好处是，您可以根据需要在任意多个对象上多次重用该接口。

祝你好运。

用DRY将对象文字转换为类型

只做:

const myObject = {
   hello: 'how are you',
   hey: 'i am fine thank you'
}

type myObjectType = keyof typeof MyObject

完成工作!

你可以使用预定义的实用程序类型Record<Keys, type >:

const obj: Record<string, string> = {
  property: "value",
};

它允许为你的对象文字指定键:

type Keys = "prop1" | "prop2"

const obj: Record<Keys, string> = {
  prop1: "Hello",
  prop2: "Aloha",
  something: "anything" // TS Error: Type '{ prop1: string; prop2: string; something: string; }' is not assignable to type 'Record<Keys, string>'.
                        //   Object literal may only specify known properties, and 'something' does not exist in type 'Record<Keys, string>'.
};

属性值的类型:

type Keys = "prop1" | "prop2"
type Value = "Hello" | "Aloha"

const obj1: Record<Keys, Value> = {
  prop1: "Hello",
  prop2: "Hey", // TS Error: Type '"Hey"' is not assignable to type 'Value'.
};

要小心了。这对一些人来说可能是显而易见的，但类型声明:

const foo: TypeName = {}

与as的铸造相比不一样:

const foo = {} as TypeName

尽管有人建议把它用在其他答案上。

例子:

谢谢,类型安全!：

const foo: { [K in 'open' | 'closed']: string } = {}
// ERROR: TS2739: Type '{}' is missing the following properties from type '{ open: string; closed: string; }': open, closed

再见,类型安全!：

const foo = {} as { [K in 'open' | 'closed']: string }
// No error