How To Get Response Synchronously And Request Asynchronously?

var arr = [1, 2, 3, 4, 5, 6, 7, 8, 9, 10]; outArr = []; var fetchData = async (str) => { var b = await fetch('http://api.mathjs.org/v4/?expr=' + str); var c = await b.

Solution 1:

You can't make anything asynchronous synchronous - instead, the best way would be to make abcasync and await each iteration. (That's if you don't want to make all requests at once - if you're OK making all requests at once, use Promise.all instead)

You should also take care not to implicitly create global variables as you're doing with outArr and len.

Here's how you would do it with await:

const fetchData = async (str) => {
  const b = awaitfetch('https://api.mathjs.org/v4/?expr=' + str);
  return b.json();
}
asyncfunctionabc() {
  const output = [];
  for (const i ofArray.from({ length: 10 }, (_, i) => i + 1)) {
    const str = i + '*' + i;
    const result = awaitfetchData(str);
    output.push(result);
  }
  return output;
}
abc()
  .then(output => {
    console.log(output);
  });

(mathjs has a certificate problem, so you may need to add an exception in your browser for the snippet to work)

Solution 2:

Use the index as first parameter. Call fetchData as follows:

fetchData(index, expr);

Within fetchData, fill an array with the result of the api call

outArr[index] = c;

Print the result or outArr!

const  arr = [1, 2, 3, 4, 5, 6, 7, 8, 9, 10];
const outArr = [];
let count = 0;

const fetchData = async (i, str) => {
  var b = awaitfetch("https://api.mathjs.org/v4/?expr=" + str);
  var c = await b.json();
  outArr[i] = c;
  count++
  if (count === arr.length) {
    console.log(outArr);
  }
};

functioncompute(arr) {
  len = arr.length;

  for (let i = 0; i < len; i++) {
    var str = i + "*" + i;
    fetchData(i, str);
  }
}

compute(arr);