If Typescript is the first language in which you've encountered generics, the concept can be quite difficult to understand. We skip the lecture in this lesson and dive straight into a real-world use-case that is guaranteed to help you understand the…

We usually think of types as something that can define a single layer of an object: with an interface we normally specify a list of a few properties and their respective types. If any one of those properties is another object we must refer again to i…

It can be painful to write the same function repeatedly with different types. Typescript generics allow us to write 1 function and maintain whatever type(s) our function is given. This lesson covers syntax and a basic use case for Typescript generics…

In this lesson we cover the key reason why programming languages need generics. We then show how use them effectively with TypeScript. We show plenty of examples where generics prevent common programming mistakes. class Query<T> { protected items: T…

Lookup types, introduced in TypeScript 2.1, allow us to dynamically create types based on the property keys of an object. We'll use the function spyOn from Jest to illustrate how lookup types can type-safe function parameters. Considering this code:…

该文章用于督促自己学习TypeScript,作为学笔记进行保存,如果有错误的地方欢迎指正 2019-03-27  16:50:03 一.什么是TypeScript? TypeScript是javascript的超集,在ts中可以使用所有的js代码,并对js进行了扩展,包括类型效验,数据类型,接口等 如图所示,TypeScript包含了javascript并进行延伸 二.准备工作 在说TypeScript之前先说一下如何让ts编译为js代码 首先安装 typescrpt, npm install…

A literal type is a type that represents exactly one value, e.g. one specific string or number. You can combine literal types with union types to model a finite set of valid values for a variable. In this lesson, we explore the all kinds of literal t…

Some functions may have different return types depending on the types of the arguments with which they’re invoked. Using TypeScript’s function overloads, you can create an overload for each allowed combination of parameter and return types. This way,…

ypeScript 2.2 introduced the object, a type that represents any non-primitive type. It can be used to more accurately type methods such as Object.create. Don't confuse it with the Object type or {}, the empty object type, though! So one thing we need…

Typescript classes make traditional object oriented programming easier to read and write. In this lesson we learn about class syntax, what the constructor is and some interesting variable features. interface Opponent { health: number; alias: string;…