[英]TypeScript classes and interfaces
I have the following typescript code:- 我有以下打字稿代码:
export class Parent {
name: string;
details: Details = {};
}
export interface Details {
age?: number;
address?: Address};
}
export interface Address {
address1: string;
address2: string;
}
Then I can reference this code to set some values:- 然后,我可以参考此代码来设置一些值:
var myOptions = new HSCIC.Visualisation.Services.Parent();
myOptions.name = "Chris";
myOptions.details.age = 25;
myOptions.details.address.address1 = "10 The Lane";
The first two setters are working fine but I get a 'Cannot set property 'address1' of 'undefined'. 前两个设置器工作正常,但是我得到的“无法设置属性'address1'为'undefined'。
If I can set the age property from Details, then why can't I set the address1 property of Address, and how can I fix it? 如果可以从“详细信息”中设置age属性,那么为什么不能设置Address的address1属性,如何解决呢?
Because you wrote: 因为您写道:
address?: Address};
But for the code to be valid, it should be: 但是,要使代码有效,应为:
address?: Address = {address1: null, address2: null};
You need to assign a value to address, just like you did in details: Details = {};
您需要为地址分配一个值,就像您在
details: Details = {};
所做的一样details: Details = {};
, or it will be undefined. ,否则它将是未定义的。 To do it this way, Details would need to be defined as a class, not an interface.
为此,需要将Details定义为一个类,而不是一个接口。 Writing
: Address
does not instantiate a new class, it only specifies the type. 编写
: Address
不会实例化新类,它仅指定类型。 Alternatively, you can make address1 and 2 optional like you did address, using ?
另外,您可以像使用地址一样将address1和2设为可选
?
, and then just write address?: Address = {};
,然后只写
address?: Address = {};
If you don't want to define Details as a class, you could write details: Details = {address:{}};
如果您不想将Details定义为一个类,则可以编写
details: Details = {address:{}};
under Parent. 在父项下
声明:本站的技术帖子网页,遵循CC BY-SA 4.0协议,如果您需要转载,请注明本站网址或者原文地址。任何问题请咨询:yoyou2525@163.com.