当课程计算属性时,用于现场初始化的速记



假设我有一个非常简单的类,带有计算的属性:

class Person {
  firstName: string;
  lastName: string;
  get fuillName(): string {
    return this.firstName + ' ' + this.lastName;
  }
}

现在我想创建一个类型Person的对象:

let p: Person = {
  firstName: 'John',
  lastName: 'Smith'
};

这给了我一个错误:

类型'{firstName:string;lastName:string;}'不能分配"人"。类型'{firstName:string;lastName:string;}'。

嗯?fullName是仅阅读属性。因此,我遵循了这个问题,并实现了部分初始化器:

constructor(init?: Partial<Person>) {
  Object.assign(this, init);
}

相同的错误。我知道我可以这样做:

let p = new Person();
p.firstName = 'John';
p.lastName = 'Smith';
console.debug(p.fullName);

但是是否有速记可以使用JSON语法初始化类?

如果您定义了类别的类:

  class Person {
    firstName?: string;
    lastName?: string;
    constructor(values: Object = {}) {
      Object.assign(this, values);
    }
    get fullName(): string {
       return this.firstName + ' ' + this.lastName;
    }
  }

您可以将新用户初始化为以下内容:

  let p = new Person({firstName : 'John', lastName: 'Smith'}); //one line, two assignations
  console.log(p.fullName); 

走得更远:

  class Person {
     ....// as above
     set fullName(fullName: string){
         let splitName = fullName.split(" ");
         this.firstName = splitName[0] || '';
         this.lastName = splitName[1] || '';
     }
   }
   let p = new Person()
   p.fullName = "Paul Doe";

plunker demo

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