typescript 从对象数组中获取属性的值
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get value of a property from array of objects
提问by avokrado
I'm building angular2 app with TypeScript and i came across a problem (note that i'm a noob in angular2 and typescript).
我正在使用 TypeScript 构建 angular2 应用程序，但遇到了一个问题（请注意，我是 angular2 和 typescript 的菜鸟）。
Problem is identical to this: From an array of objects, extract value of a property as arraybut since i'm not using JavaScript, provided solution isn't very helpful (or is it?)
问题与此相同：从对象数组中，将属性的值提取为数组，但由于我没有使用 JavaScript，因此提供的解决方案不是很有帮助（或者是吗？）
I'm getting JSON objects from API and simply save them in array:
我从 API 获取 JSON 对象并将它们保存在数组中：
constructor(private namelistService: NameListService) { }
getAllDevices(){
this.namelistService.getDevices()
.subscribe(
data => this.devices = data,
error => console.log('Server error'),
);
}
also my simple service:
还有我的简单服务：
constructor(private http:Http){}
getDevices(): Observable<any>{
return this.http.get("http://link-to-api")
.map( (res: Response) => res.json())
.catch((error: any) => Observable.throw(error.json().error || 'Server error'));
}
resulting in objects like this (i deleted the values):
导致这样的对象（我删除了值）：
{
"_id": "",
"info": {
"device_id": ,
"device_name": "",
"uid": "",
"firmware": "",
"hardware": "",
"description": ""
},
All i want to do is to get the _id values from every object in array and save it in seperate array: arr2 = [id1, id2, id3, id4, ... ]
我想要做的就是从数组中的每个对象中获取 _id 值并将其保存在单独的数组中： arr2 = [id1, id2, id3, id4, ... ]
采纳答案by eko
You can pretty much use any javascript code inside a typescript code since typescript is compiled into javascript itself.
您几乎可以在打字稿代码中使用任何 javascript 代码，因为打字稿已编译为 javascript 本身。
constructor(private namelistService: NameListService) { }
resultArray:any;
getAllDevices(){
this.namelistService.getDevices()
.subscribe(
(data) => {
this.devices = data;
this.resultArray = this.devices.map(function(a) {return a["_id"];});
},
error => console.log('Server error'),
);
}
