单击按钮后不等待页面加载的JavaScript代码

function handleClick() {
  var xhr = new XMLHttpRequest();
  xhr.open('GET', 'https://example.com/data', true);
  xhr.onreadystatechange = function() {
    if (xhr.readyState === 4 && xhr.status === 200) {
      // 处理返回的数据
      var response = JSON.parse(xhr.responseText);
      console.log(response);
    }
  };
  xhr.send();
}

document.getElementById('myButton').addEventListener('click', handleClick);

function handleClick() {
  fetch('https://example.com/data')
    .then(function(response) {
      if (response.ok) {
        return response.json();
      }
      throw new Error('Network response was not ok.');
    })
    .then(function(data) {
      // 处理返回的数据
      console.log(data);
    })
    .catch(function(error) {
      console.log('Error:', error);
    });
}

document.getElementById('myButton').addEventListener('click', handleClick);