TypeScript 备忘清单

Uppercase<StringType>

type Greeting = "Hello, world"
type ShoutyGreeting = Uppercase<Greeting>
// type ShoutyGreeting = "HELLO, WORLD"

type ASCIICacheKey<Str extends string> = `ID-${Uppercase<Str>}`
type MainID = ASCIICacheKey<"my_app">
// type MainID = "ID-MY_APP"

将字符串中的每个字符转换为大写版本。

Lowercase<StringType>

type Greeting = "Hello, world"
type QuietGreeting = Lowercase<Greeting>
// type QuietGreeting = "hello, world"

type ASCIICacheKey<Str extends string> = `id-${Lowercase<Str>}`
type MainID = ASCIICacheKey<"MY_APP">
// type MainID = "id-my_app"

将字符串中的每个字符转换为等效的小写字母。

Capitalize<StringType>

type LowercaseGreeting = "hello, world";
type Greeting = Capitalize<LowercaseGreeting>;
// type Greeting = "Hello, world"

将字符串中的第一个字符转换为等效的大写字母。

Uncapitalize<StringType>

type UppercaseGreeting = "HELLO WORLD";
type UncomfortableGreeting = Uncapitalize<UppercaseGreeting>;
// type UncomfortableGreeting = "hELLO WORLD"

将字符串中的第一个字符转换为等效的小写字母。