如何等待所有xhr请求完成？

function makeRequest(url) {
  return new Promise((resolve, reject) => {
    const xhr = new XMLHttpRequest();
    xhr.open('GET', url);
    xhr.onload = () => resolve(xhr.responseText);
    xhr.onerror = () => reject(xhr.statusText);
    xhr.send();
  });
}

const urls = ['url1', 'url2', 'url3'];
Promise.all(urls.map(makeRequest))
  .then(responses => {
    console.log('All requests completed', responses);
  })
  .catch(error => {
    console.error('An error occurred', error);
  });

function makeRequest(url, callback) {
  const xhr = new XMLHttpRequest();
  xhr.open('GET', url);
  xhr.onload = () => callback(null, xhr.responseText);
  xhr.onerror = () => callback(xhr.statusText);
  xhr.send();
}

const urls = ['url1', 'url2', 'url3'];
let completedRequests = 0;
const results = [];

function checkAllRequestsCompleted() {
  if (completedRequests === urls.length) {
    console.log('All requests completed', results);
  }
}

urls.forEach(url => {
  makeRequest(url, (error, response) => {
    if (error) {
      console.error('An error occurred', error);
    } else {
      results.push(response);
      completedRequests++;
      checkAllRequestsCompleted();
    }
  });
});

async function makeRequest(url) {
  return new Promise((resolve, reject) => {
    const xhr = new XMLHttpRequest();
    xhr.open('GET', url);
    xhr.onload = () => resolve(xhr.responseText);
    xhr.onerror = () => reject(xhr.statusText);
    xhr.send();
  });
}

async function fetchAllRequests() {
  const urls = ['url1', 'url2', 'url3'];
  try {
    const responses = await Promise.all(urls.map(makeRequest));
    console.log('All requests completed', responses);
  } catch (error) {
    console.error('An error occurred', error);
  }
}

fetchAllRequests();