Question

假设具有此接口： Employee.model.ts：

interface EmployeeInterface{
    name: string;
    salary?: number;
    date: Date;
}

我知道该怎么做：

export class Employee implements EmployeeInterface{
    public name: string;
    public salary: number;
    public date: Date;
}

我的问题是我如何在构造函数中指定薪水参数可以或不能？

Answer 1

您只需将字段定义为参数构造函数（通过向参数添加可见性修饰符），然后将适当的字段和参数标记为可选（但您需要将其放在参数列表的末尾）：

interface ObjectToSellInterface{
  name: string;
  salary?: number;
  date: Date;
}
export class ObjectToSell implements ObjectToSellInterface{
  public constructor(
    public name: string,
    public date: Date, 
    public salary?: number){ }
}

上面的代码等同于：

export class ObjectToSell implements ObjectToSellInterface{

  public name: string;
  public date: Date;
  public salary?: number;

  public constructor(
    name: string,
    date: Date, 
    salary?: number){ 
      this.date = date;
      this.name = name;
      this.salary = salary;
    }
}

Typescript类如何指定该元素可以是可选的

1 个答案: