Type 有一个类似的实用程序类型，称为 NonNullable，其实现如下： type NonNullable<T> = T extendsnull | undefined? never : T; NonNullable 和 NoNull 之间的区别在于 NonNullable 将从类型中删除 undefined 以及 null。 （3）条件类型的类型推断 ...

Bug Report 🔎 Search Terms defer, index access, index signature, nonnullable 🕗 Version & Regression Information This somewhat changed between versions 4.7 and 4.8 ⏯ Playground Link Playground link w ...

我们将类型 NonNullableType 作为参数传递给 NonNullable ， NonNullable 通过排除 null 和 undefined 来构造新类型。 也就是说，如果你传递可为空的值，Type 将引发错误。 顺便说一句，如果将 --strictNullChecks 标志添加到 tsconfig文件 ，Type 将应用非空性规则。 Mapped Types ( 映射类型) ...

All reactions mgol changed the title NonNullable isn't narrowing down object values' types NonNullable isn't narrowing down object values' types for optional properties on Nov 6, 2018 weswigham added ...

Additionally, TypeScript adds a number of new type aliases (Exclude, Extract, InstanceType, NonNullable, ReturnType) that leverage conditional types via lib.d.ts.