TS提供了getter和setter，使对象属性能够更好地控制如何在对象外部访问(getter)或更新(setter)。不是直接访问或更新属性，而是调用代理函数。

例子:

class Person {
    constructor(name: string) {
        this._name = name;
    }

    private _name: string;

    get name() {
        return this._name;
    }

    // first checks the length of the name and then updates the name.
    set name(name: string) {
        if (name.length > 10) {
            throw new Error("Name has a max length of 10");
        }

        this._name = name;  
    }

    doStuff () {
        this._name = 'foofooooooofoooo';
    }


}

const person = new Person('Willem');

// doesn't throw error, setter function not called within the object method when this._name is changed
person.doStuff();  

// throws error because setter is called and name is longer than 10 characters
person.name = 'barbarbarbarbarbar';  

Ezward已经提供了一个很好的答案，但我注意到其中一个评论问它是如何使用的。对于像我这样偶然遇到这个问题的人，我认为在Typescript网站上有一个关于getter和setter的官方文档的链接会很有用，因为它能很好地解释它，并希望在发生更改时始终保持最新，并显示示例用法:

http://www.typescriptlang.org/docs/handbook/classes.html

特别地，对于那些不熟悉它的人，请注意，在调用getter时不要合并'get'这个词(setter也是如此):

var myBar = myFoo.getBar(); // wrong    
var myBar = myFoo.get('bar');  // wrong

你应该简单地这样做:

var myBar = myFoo.bar;  // correct (get)
myFoo.bar = true;  // correct (set) (false is correct too obviously!)

给定一个类:

class foo {
  private _bar:boolean = false;

  get bar():boolean {
    return this._bar;
  }
  set bar(theBar:boolean) {
    this._bar = theBar;
  }
}

然后私有属性'_bar'的'bar' getter将被调用。

TS提供了getter和setter，使对象属性能够更好地控制如何在对象外部访问(getter)或更新(setter)。不是直接访问或更新属性，而是调用代理函数。

例子:

class Person {
    constructor(name: string) {
        this._name = name;
    }

    private _name: string;

    get name() {
        return this._name;
    }

    // first checks the length of the name and then updates the name.
    set name(name: string) {
        if (name.length > 10) {
            throw new Error("Name has a max length of 10");
        }

        this._name = name;  
    }

    doStuff () {
        this._name = 'foofooooooofoooo';
    }


}

const person = new Person('Willem');

// doesn't throw error, setter function not called within the object method when this._name is changed
person.doStuff();  

// throws error because setter is called and name is longer than 10 characters
person.name = 'barbarbarbarbarbar';  

你可以这样写

class Human {
    private firstName : string;
    private lastName : string;

    constructor (
        public FirstName?:string, 
        public LastName?:string) {

    }

    get FirstName() : string {
        console.log("Get FirstName : ", this.firstName);
        return this.firstName;
    }
    set FirstName(value : string) {
        console.log("Set FirstName : ", value);
        this.firstName = value;
    } 

    get LastName() : string {
        console.log("Get LastName : ", this.lastName);
        return this.lastName;
    }
    set LastName(value : string) {
        console.log("Set LastName : ", value);
        this.lastName = value;
    } 

}

我想我大概知道为什么这么令人困惑了。在您的示例中，我们需要_name的getter和setter。但我们通过为不相关的类变量Name创建getter和setter来实现这一点。

考虑一下:

class Car {
    private tiresCount = 4;
    get yourCarTiresCount(){
        return this.tiresCount;
    }
    set yourCarTiresCount(count) {
        alert('You shouldn\'t change car tire count')
    }
}

上面的代码如下:

get和set为yourCarTiresCount创建getter和setter(不是为tiresCount)。

getter是:

function () {
    return this.tiresCount;
}

setter是:

function (count) {
    alert('You shouldn\'t change car tire count');
}

意思是，每次执行new Car()。yourCarTiresCount, getter运行。并且对于每一个新的Car(). yourcartirescount ('7') setter运行。

间接地为私有ti复述创建getter，而不是setter。

如果你正在使用TypeScript模块，并试图添加一个导出的getter，你可以这样做:

// dataStore.ts
export const myData: string = undefined;  // just for typing support
let _myData: string;  // for memoizing the getter results

Object.defineProperty(this, "myData", {
    get: (): string => {
        if (_myData === undefined) {
            _myData = "my data";  // pretend this took a long time
        }

        return _myData;
    },
});

然后，在另一个文件中:

import * as dataStore from "./dataStore"
console.log(dataStore.myData); // "my data"