不能将“BModel[]”转换为“IBData”类型

Question

下面有一个类似的类，它实现了一个IBData接口。

export class BModel implements IBData{

}

在API响应之后，我将数据分配给私有变量accountBalanceData，它的类型为IBData。

this.accountBalanceData  = data; 

我从api响应调用获得的数据是BModel类型的，即类本身。

我得到了下面的error

[ts] Type 'BModel[]' is not assignable to type 'IBData'.
[ts]
Type 'BModel[]' is not assignable to type 'IBData'.
  Property 'getAcBal' is missing in type 'BModel[]'.

我尝试了下面的typecast

this.accountBalanceData  = data as IBData; 

我得到了下面的error

[ts] Type 'BModel[]' cannot be converted to type 'IBData'.
[ts]
Type 'BModel[]' cannot be converted to type 'IBData'.
  Property 'getAcBal' is missing in type 'BModel[]'.

更新：

.map(res => {            
   res["_body"] = res["_body"].replace(/[\n\r\t]+/g,"");
   this.BModel.data = res["_body"]
   return this.BModel;
 }) 

Answer 1

函数map返回一个对象数组，因此该表达式的结果类型

.map(res => {            
   res["_body"] = res["_body"].replace(/[\n\r\t]+/g,"");
   this.BModel.data = res["_body"]
   return this.BModel;
 }) 

将是BModel[]