I'm trying to learn async functions and am struggling to get the following to work.

async get_price(ticker) {
  var price = await axios
    .get(`https://marketwebsite.com/${ticker}`, {
      headers: {
        "User-Agent":
          "Mozilla/5.0 (Macintosh; Intel Mac OS X 10_15_7) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/99.0.4844.74 Safari/537.36",
      },
    })
    .then((res) => {
      const $ = cheerio.load(res.data);
      $(".todays_price").each((index, element) => {
        var value = $(element)
          .find(".current_price")
          .text()
          .replace(/\s\s /g, "");
        return value;
        console.log(value); // THIS WORKS
      });
    })
    .catch((err) => console.error(err));
}

When i call

var price = get_price(symbol); 

I cannot get any return from this function. The console log noted above does work, however i cannot get the value to return from this function.

I have tried to await get_price(symbol) as well.

CodePudding user response：

There are a few issues in your snippet including:

• You are not returning price from your get_price function
• You are not returning anything in your .then() call

Try the following snippet:

async function get_price(ticker) {
  return await axios
    .get(`https://marketwebsite.com/${ticker}`)
    .then((res) => {
      const $ = cheerio.load(res.data);
      return $(".todays_price").map((index, element) => {
        var value = $(element)
          .find(".current_price")
          .text()
          .replace(/\s\s /g, "");
        return value;
      });
    })
    .catch((err) => console.error(err));
}

get_price('ticker').then((res) => {
  console.log(res); // Should print array of the values
});

I've used the jQuery .map method as it seems like you intended to return the values for each element.

I suggest going through the documentation on async await and promises on the MDN docs. https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Promise https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Statements/async_function

CodePudding user response：

there are two things:

first, the code in the then() block is returned to price variable that isn't returned

second, var price = get_price(symbol); the function call is not using await so if you log that you will get the promise instead of the value.

you need to return the axios call and await it when using the function elsewhere