TypeStript 入门 - 12：扩展变量类型 #

//! declare 包裹声明
declare global {
	//! 1. 拓展全局类型String的方法声明
	interface String {
		double(): string;
	}
}

//! 1. 实现拓展全局类型String的方法
String.prototype.double = function () {
	return this + "," + this;
}

let str = 'pt';
console.log(str.double());

//! 1.同名interface合并：利用interface 把多个同名interface声明合并
interface Animal {
	name: string
}
interface Animal {
	age: number
}

let a: Animal = { name: 'pt', age: 18 };

//! 2.扩展类: class 与namespace 合并
class Form { }
namespace Form {
	export const type = 'form'
}

let f1: Form = { type: "xx" };
console.log(Form.type);	//form
console.log(f1);				//{type:'xx'}

//! 3.拓展方法: function 与 namespace 合并
function getName() { }
namespace getName {
	export const type = 'form'
}
console.log(getName.type);//form

//! 4.拓展枚举：enum 与 namespace 合并
enum Seasons {
	Spring = 'Spring',
	Summer = 'Summer'
}
namespace Seasons {
	export let Autumn = 'Autumn';
	export let Winter = 'Winter'
}
console.log(Seasons.Spring);//Spring
console.log(Seasons.Autumn);//Autumn

type Animal = {
	age: Number
}

type Person = {
	name: String
}

type PersonInfo = Animal & Person & {
	address: string
}

let personInfo: PersonInfo;
personInfo = { age: 11, name: "pt", address: "123" };