I have a small problem, I need to fetch data while loading page in for loop. I have an async function to return result, and it's returning result from a server, but it only shows in console.log() but to my object goes only promise object. Can someone explain to me how to do this in proper way ?

JSON

 let a = {
        createdAt: "2021-11-06T11:03:15.917 0000",
        updatedAt: "2021-11-06T11:03:15.917 0000",
        version: 0,
        scheduleDate: "2021-09-24",
        schedule: [
          {
            date: "2021-09-24",
            breakfast: 1,
            secondBreakfast: 1,
            lunch: 1,
            dinner: 1,
            supper: 1,
            prepareTime: 55,
            calorific: 33.4,
            protein: 1.1,
            fat: 0.2,
            carbohydrates: 7.1,
            roughage: 0.4,
          },
          {
            date: "2021-09-25",
            breakfast: 1,
            secondBreakfast: 1,
            lunch: 1,
            dinner: 1,
            supper: 1,
            prepareTime: 55,
            calorific: 33.4,
            protein: 1.1,
            fat: 0.2,
            carbohydrates: 7.1,
            roughage: 0.4,
          },
          {
            date: "2021-09-26",
            breakfast: 1,
            secondBreakfast: 1,
            lunch: 1,
            dinner: 1,
            supper: 1,
            prepareTime: 55,
            calorific: 33.4,
            protein: 1.1,
            fat: 0.2,
            carbohydrates: 7.1,
            roughage: 0.4,
          },
          {
            date: "2021-09-27",
            breakfast: 1,
            secondBreakfast: 1,
            lunch: 1,
            dinner: 1,
            supper: 1,
            prepareTime: 55,
            calorific: 33.4,
            protein: 1.1,
            fat: 0.2,
            carbohydrates: 7.1,
            roughage: 0.4,
          },
          {
            date: "2021-09-28",
            breakfast: 1,
            secondBreakfast: 1,
            lunch: 1,
            dinner: 1,
            supper: 1,
            prepareTime: 55,
            calorific: 33.4,
            protein: 1.1,
            fat: 0.2,
            carbohydrates: 7.1,
            roughage: 0.4,
          },
          {
            date: "2021-09-29",
            breakfast: 1,
            secondBreakfast: 1,
            lunch: 1,
            dinner: 1,
            supper: 1,
            prepareTime: 55,
            calorific: 33.4,
            protein: 1.1,
            fat: 0.2,
            carbohydrates: 7.1,
            roughage: 0.4,
          },
          {
            date: "2021-09-30",
            breakfast: 1,
            secondBreakfast: 1,
            lunch: 1,
            dinner: 1,
            supper: 1,
            prepareTime: 55,
            calorific: 33.4,
            protein: 1.1,
            fat: 0.2,
            carbohydrates: 7.1,
            roughage: 0.4,
          },
        ],
        memberId: 1,
        id: 49,
      };
 this.parseMemberScheduleData(a);

 parseMemberScheduleData(aSchedule) {
      let arr = [];
      for (let i = 0; i < aSchedule.schedule.length; i  ) {
        arr.push({
          data: aSchedule.schedule[i].date,
          meals: {
            breakfast: this.fetchMealDetails(aSchedule.schedule[i].breakfast),
            secondBreakfast: this.fetchMealDetails(
              aSchedule.schedule[i].secondBreakfast
            ),
            dinner: this.fetchMealDetails(aSchedule.schedule[i].dinner),
            lunch: this.fetchMealDetails(aSchedule.schedule[i].lunch),
            supper: this.fetchMealDetails(aSchedule.schedule[i].supper),
          },
          mealsId: {
            breakfast: aSchedule.schedule[i].breakfast,
            secondBreakfast: aSchedule.schedule[i].secondBreakfast,
            dinner: aSchedule.schedule[i].dinner,
            lunch: aSchedule.schedule[i].lunch,
            supper: aSchedule.schedule[i].supper,
          },
        });
      }

 async fetchMealDetails(aId) {
      let requestOptions = {
        method: "GET",
        redirect: "follow",
      };
      try {
        let responce = await fetch(`${MEALS}${aId}`, requestOptions);
        let result = await responce.json();
  console.log("~ result", result);
        return result;
      } catch (err) {
        console.log(err);
      }
    },

CodePudding user response：

You get the Promise returned because you don't await for the result in the for loop

 async function parseMemberScheduleData(aSchedule) {
      let arr = [];
      for (let i = 0; i < aSchedule.schedule.length; i  ) {
        arr.push({
          data: aSchedule.schedule[i].date,
          meals: {
            breakfast: await this.fetchMealDetails(aSchedule.schedule[i].breakfast),
            secondBreakfast: await this.fetchMealDetails(
              aSchedule.schedule[i].secondBreakfast
            ),
            dinner: await this.fetchMealDetails(aSchedule.schedule[i].dinner),
            lunch: await this.fetchMealDetails(aSchedule.schedule[i].lunch),
            supper: await this.fetchMealDetails(aSchedule.schedule[i].supper),
          },
          mealsId: {
            breakfast: aSchedule.schedule[i].breakfast,
            secondBreakfast: aSchedule.schedule[i].secondBreakfast,
            dinner: aSchedule.schedule[i].dinner,
            lunch: aSchedule.schedule[i].lunch,
            supper: aSchedule.schedule[i].supper,
          },
        });
      }
    //I don't know the function that calls this but if this function returns everything.. you must await parseMemberScheduleData(theData)