To avoid using "any" type is a best pratice. The reason for that is it disable the power of typescirpt to helping check you during the compile time. For example: currency(num: number){ cosnole.log(num.toFixed()); } In our currency function, it s…

TypeScript 2.0 introduced a new primitive type called never, the type of values that never occur. It helps model the completion behavior of functions more accurately and can also be used for exhaustiveness checking. never type means that 'That part o…

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…

One aspect of control flow based type analysis is that the TypeScript compiler narrows the type of a variable within a type guard. This lesson explores how you can define functions and type predicates to create your own type guards similar to the Arr…

To fix Promise is not recolized in TypeScript, we can choose to use a lib: npm i @types/es6-promise we can also use built-in libs: { "compilerOptions": { "module": "commonjs", "target": "es5", "noImpl…

In redux, the action type is just a normal string type, it is easy to get naming conflicts in large application. Can use namespace-constants lib to solve the problem: https://npmdaily.com/pkg/namespace-constants import constants from 'namespace-const…

在接触 ts 相关代码的过程中,总能看到 interface 和 type 的身影.只记得,曾经遇到 type 时不懂查阅过,记得他们很像,相同的功能用哪一个都可以实现.但最近总看到他们,就想深入的了解一下他们. interface:接口 TypeScript 的核心原则之一是对值所具有的结构进行类型检查. 而接口的作用就是为这些类型命名和为你的代码或第三方代码定义契约. interface LabelledValue { label: string; } function printLabel…

原文: https://www.sitepoint.com/10-essential-typescript-tips-tricks-angular/ -------------------------------------------------------------------------------------------------------------------------------------------------------------------------------…

CSS不像其它高级语言一样支持算术运算.变量.流程控制与面向对象特性,所以CSS样式较多时会引起一些问题,如修改复杂,冗余,某些别的语言很简单的功能实现不了等.而javascript则是一种半面向对象的动态语言,有java的影子,有C的味道,中间有比其它语言多的糟粕,使用预处理办法可以解决这些问题.其中Less[les]与Sass是CSS的预处理技术,而CoffeeScript.TypeScript则是javascript的预处理技术. 一.Less 1.1.概要 Less是一种动态样式语言,L…

CSS不像其它高级语言一样支持算术运算.变量.流程控制与面向对象特性,所以CSS样式较多时会引起一些问题,如修改复杂,冗余,某些别的语言很简单的功能实现不了等.而javascript则是一种半面向对象的动态语言,有java的影子,有C的味道,中间有比其它语言多的糟粕,使用预处理办法可以解决这些问题.其中Less[les]与Sass是CSS的预处理技术,而CoffeeScript.TypeScript则是javascript的预处理技术. 一.Less 1.1.概要 Less是一种动态样式语言,L…