javascript - 如何在ajax成功方法中获取数组值？

Question

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我想重定向到ajax之后最快的URL调用了所有 URL，但是当我警告该值时，我得到 undefined :

var servers = ["url1", "url2", "url3"];
for (var i = 0; i < servers.length; i++) {
  $.ajax({
    type: "GET",
    url: servers[i],
    data: {},
    cache: false,
    success: function(output) { 
      // window.location.href = servers[i]
      alert(servers[i]);
    }
  });
}

Answer 1

您可以使用Promise.race代替迭代。 MDN

const servers = ["url1", "url2", "url3"];
const requests = servers.map(server => $.ajax({...}));

Promise.race(requests)
    .then(/* handle the fastest request */)
    .catch(/* catch error here */)