等待map函数完成typescript

for-each循环不等待map函数完成，因此id未定义。 如何确保所有id都已映射

getIndexes(){
 this.http.get<{data: {id: number, caption:string}[], paging: any, next: string}>(this.baseUrl +'me/media/?access_token=' + this.users + '&fields=id,caption&limit=9',
{responseType:"json"}).subscribe(response =>
  {
    const data = response.data.map(async l => {
      l.id
    })
    data.forEach(
    id => {
      this.http.get<{ media_url: string; id: string; }>(this.baseUrl + id + '/?access_token=' + this.users + '&fields=media_url').subscribe(res => {
        console.log(this.list);
        this.list.push(res.media_url);
        console.log(this.list);
        this.gallery.next(this.list);
      });
    }

  );
  }
)
}

getindex（）{
this.http.get（this.baseUrl+'me/media/？access_token='+this.users+'&fields=id，caption&limit=9'，
{responseType:“json”}）.subscribe（response=>
{
const data=response.data.map（异步l=>{
l、 身份证
})
data.forEach(
id=>{
this.http.get（this.baseUrl+id+'/？access_-token='+this.users+'&fields=media_-url'）。订阅（res=>{
console.log（this.list）；
this.list.push（res.media\u url）；
console.log（this.list）；
this.gallery.next（this.list）；
});
}
);
}
)
}

试着像这样使用wait

getIndexes(){
 this.http.get<{data: {id: number, caption:string}[], paging: any, next: string}>(this.baseUrl +'me/media/?access_token=' + this.users + '&fields=id,caption&limit=9',
{responseType:"json"}).subscribe(async response =>
  {
    const data =await response.data.map(l => {
      l.id
    })
    data.forEach(
    id => {
      this.http.get<{ media_url: string; id: string; }>(this.baseUrl + id + '/?access_token=' + this.users + '&fields=media_url').subscribe(res => {
        console.log(this.list);
        this.list.push(res.media_url);
        console.log(this.list);
        this.gallery.next(this.list);
      });
    }

  );
  }
)
}

getindex（）{
this.http.get（this.baseUrl+'me/media/？access_token='+this.users+'&fields=id，caption&limit=9'，
{responseType:“json”}）.subscribe（异步响应=>
{
const data=wait response.data.map（l=>{
l、 身份证
})
data.forEach(
id=>{
this.http.get（this.baseUrl+id+'/？access_-token='+this.users+'&fields=media_-url'）。订阅（res=>{
console.log（this.list）；
this.list.push（res.media\u url）；
console.log（this.list）；
this.gallery.next（this.list）；
});
}
);
}
)
}