javascript - 获取数组对象类型脚本中的第一个索引

Question

我想在下面的代码片段中从数组对象 dataList 获取索引零记录。我是 JavaScript 和 Typescript 的新手。

dataList: Array<any> = [];
 data: any;

 constructor(private apiService: ApiService) {  


   this.apiService.getEncounterDashBoard(this.searchCond)
     .subscribe(data => {
       this.dataList = data.result;
     });

    let labels = this.dataList[0];
}

Answer 1

你可以这样试试

dataList: Array<any> = [];
 data: any;

 constructor(private apiService: ApiService) {  

 let labels = [];
   this.apiService.getEncounterDashBoard(this.searchCond)
     .subscribe(data => {
       this.dataList = data.result;
       labels = this.dataList[0]; 
// here you can see that we are access the data inside the subscription block bcs javascript is asynchronous. So it is not wait complete the api call 
     });
}