学习TypeScript 命名空间

命名空间一个最明确的目的就是解决重名问题。
命名空间使用 namespace 来定义，语法格式如下：

namespace SomeNameSpaceName {
export interface ISomeInterfaceName { }
export class SomeClassName { }
}

要在另外一个命名空间调用语法格式为：

SomeNameSpaceName.SomeClassName;

如果一个命名空间在一个单独的 TypeScript 文件中，则应使用三斜杠 /// 引用它，语法格式如下：

/// <reference path = "SomeFileName.ts" />

namespace Drawing { 
    export interface IShape { 
        draw(); 
    }
}

/// <reference path = "IShape.ts" /> 
namespace Drawing { 
    export class Circle implements IShape { 
        public draw() { 
            console.log("Circle is drawn"); 
        }  
    }
}

/// <reference path = "IShape.ts" /> 
namespace Drawing { 
    export class Triangle implements IShape { 
        public draw() { 
            console.log("Triangle is drawn"); 
        } 
    } 
}

/// <reference path = "IShape.ts" />   
/// <reference path = "Circle.ts" /> 
/// <reference path = "Triangle.ts" />  
function drawAllShapes(shape:Drawing.IShape) { 
    shape.draw(); 
} 
drawAllShapes(new Drawing.Circle());
drawAllShapes(new Drawing.Triangle());

/// <reference path = "IShape.ts" /> 
var Drawing;
(function (Drawing) {
    var Circle = /** @class */ (function () {
        function Circle() {
        }
        Circle.prototype.draw = function () {
            console.log("Circle is drawn");
        };
        return Circle;
    }());
    Drawing.Circle = Circle;
})(Drawing || (Drawing = {}));
/// <reference path = "IShape.ts" /> 
var Drawing;
(function (Drawing) {
    var Triangle = /** @class */ (function () {
        function Triangle() {
        }
        Triangle.prototype.draw = function () {
            console.log("Triangle is drawn");
        };
        return Triangle;
    }());
    Drawing.Triangle = Triangle;
})(Drawing || (Drawing = {}));
/// <reference path = "IShape.ts" />   
/// <reference path = "Circle.ts" /> 
/// <reference path = "Triangle.ts" />  
function drawAllShapes(shape) {
    shape.draw();
}
drawAllShapes(new Drawing.Circle());
drawAllShapes(new Drawing.Triangle());

嵌套命名空间

命名空间支持嵌套，可以将命名空间定义在另外一个命名空间里头。

namespace namespace_name1 {
export namespace namespace_name2 {
export class class_name { }
}
}

namespace Runoob { 
   export namespace invoiceApp { 
      export class Invoice { 
         public calculateDiscount(price: number) { 
            return price * .40; 
         } 
      } 
   } 
}