723_ajax_同源策略

发表于 2023-07-23 分类于 ajax-promise-axios 阅读次数：
<!DOCTYPE html>
<html lang="en">
  <head>
    <meta charset="UTF-8" />
    <meta name="viewport" content="width=device-width, initial-scale=1.0" />
    <title>Document</title>
  </head>
  <body>
    <h1>西南大学</h1>
    <button>点击获取用户数据</button>
    <script>
      const btn = document.querySelector("button");

      btn.onclick = function () {
        const x = new XMLHttpRequest();
        //因为这里满足同源策略，所以url可以简写
        x.open("GET", "/data");
        //发送
        x.send();
        x.onreadystatechange = function () {
          if (x.readyState == 4) {
            if (x.status >= 200 && x.status < 300) {
              console.log(x.response);
            }
          }
        };
      };
    </script>
  </body>
</html>