为什么:
let provider = new Provider();
var keys = Object.keys(provider);
console.log(keys);
返回一个空数组,时间:
let provider = { Name: '', Surname: '' };
var keys = Object.keys(provider);
console.log(keys);
返回一个包含2个属性的数组?
这是我的Provider.ts
:
export class Provider {
public Id: string;
public Name: string;
public FriendlyName: string;
public CompanyRegistrationNumber: string;
public VatRegistrationNumber: string;
public TfgUniqueReferenceNumber: string;
public Since: Date;
public Until: Date;
public DefaultBillingDay: number;
public DefaultProvisioningDay: number;
public AllowsToProvisionProRata: boolean;
public AllowsToBillProRata: boolean;
public EmailAddress: string;
public DateCreated: Date;
public DateModified: Date;
public UserCreated: string;
public UserModified: string;
public IsRetired: boolean;
public ImageUrl: string;
public ContactNumber1: ContactNumber;
public ContactNumber2: ContactNumber;
public PhysicalAddress: Address;
public PostalAddress: Address;
public FinancialSystemAccount: FinancialSystemAccount;
public WholesaleProducts: Array<WholesaleProduct>;
public ContactPeople: Array<ContactPerson>;
public Batches: Array<Batch>;
public BatchCandidates: Array<BatchCandidate>;
public AllowableBatchTypes: Array<BatchType>;
}
除非您初始化属性,否则它们实际上并未创建。您可以检查trasnpiled Provider.js
文件并进行验证。这只是一种告诉编译器的方法,每当我们在Provider
的实例中使用它时,强制执行这些预定义类型。
这个班,
class Provider {
public Id: string;
public Name: string;
public FriendlyName: string;
public CompanyRegistrationNumber: string;
public VatRegistrationNumber: string;
public TfgUniqueReferenceNumber: string;
public InitializedProp: string = '';
}
获取转换为:
var Provider = (function () {
function Provider() {
this.InitializedProp = '';
}
return Provider;
}());
您可以看到只有InitializedProp
被创建为trasnpiled构造函数中的属性。