于长野 为什么要学习 Typescript ? Static typing(静态类型化,区别于 js 的动态类型) Code completion Refactoring Shorthand notations TS 适用于一些中大型项目,使其变得便于维护 JS 更适合一些简单的项目,可以快速完成 TS 可以提前避免更多错误
于长野 声明一个对象 type Employee = { readonly id: number; name: string; retire: (date: Date) => void; }; let employee: Employee = { id: 1, name: "rabithua", retire: (date: Date) => { console.log(date); }, };
于长野 函数声明变量类型以及返回类型 function kg2Lbs(weight: number | string): number { if (typeof weight === "number") { return weight * 2.2; } else return parseInt(weight) * 2.2; } kg2Lbs(10); kg2Lbs("10");
于长野 声明类型并组合 type Draggable = { drag: () => void; }; type Resizeable = { resize: () => void; }; type UIWidget = Draggable & Resizeable; let textBox: UIWidget = { drag: () => {}, resize: () => {}, };