javascript/Typescript 在 .then 內返回 array.filter 內的回調

Question

我想過濾一個數組，但要做到這一點，我需要調用返回承諾的數據庫。 代碼：

this.arrayToFilter.filter(myObject => {
    this.dataBaseService.getSomething(myObject.id).then(something => {
        // some calculations
        return shouldBeFiltered 
    })
})

如何將shouldBeFiltered的值shouldBeFiltered到過濾器回調中？

Answer 1

創建一個Promise.all數組並在過濾之前調用Promise.all ：

const shouldBeFilteredArr = await Promise.all(
  this.arrayToFilter.map(({ id }) => this.dataBaseService.getSomething(id)
);
const filteredItems = this.arrayToFilter.filter((myObject, i) => {
  const something = shouldBeFilteredArr[i];
  // some calculations
  return shouldBeFiltered;
});