JavaScript - 如何根据唯一的 # 从数组中获取唯一的 url？

Question

我正在尝试从此数组中获取唯一的 URL。

var urls = [
"http://display.companyX.com/rest/banner?l_id=A000-0000-0000000-000000-791-0-0-0&k=A77K_fakfhaskfhkjshfkjo=kafkjafk",
"http://display.companyX.com/rest/banner?l_id=A000-0000-0000000-000000-791-0-0-0&k=A77K_fakfhaskfhkjshfkjo=kafkjafk",
"http://display.companyX.com/rest/banner?l_id=A000-0000-0000000-000000-246-0-0-0&k=A77K_fakfhaskfhkjshfkjo=kafkjafk",
"http://display.companyX.com/rest/banner?l_id=A000-0000-0000000-000000-246-0-0-0&k=A77K_fakfhaskfhkjshfkjo=kafkjafk",
"http://display.companyX.com/rest/banner?l_id=A000-0000-0000000-000000-796-0-0-0&k=A77K_fakfhaskfhkjshfkjo=kafkjafk",
"http://display.companyX.com/rest/banner?l_id=A000-0000-0000000-000000-796-0-0-0&k=A77K_fakfhaskfhkjshfkjo=kafkjafk",
"http://display.companyX.com/rest/banner?l_id=A000-0000-0000000-000000-051-0-0-0&k=A77K_fakfhaskfhkjshfkjo=kafkjafk",
"http://display.companyX.com/rest/banner?l_id=A000-0000-0000000-000000-051-0-0-0&k=A77K_fakfhaskfhkjshfkjo=kafkjafk",
"http://display.companyX.com/rest/banner?l_id=A000-0000-0000000-000000-056-0-0-0&k=A77K_fakfhaskfhkjshfkjo=kafkjafk",
"http://display.companyX.com/rest/banner?l_id=A000-0000-0000000-000000-056-0-0-0&k=A77K_fakfhaskfhkjshfkjo=kafkjafk",
]

从代码来看，第五个数组是['791','246','796','051','056']，所以输出是这样的:

[
"http://display.companyX.com/rest/banner?l_id=A000-0000-0000000-000000-791-0-0-0&k=A77K_fakfhaskfhkjshfkjo=kafkjafk",
"http://display.companyX.com/rest/banner?l_id=A000-0000-0000000-000000-246-0-0-0&k=A77K_fakfhaskfhkjshfkjo=kafkjafk",
"http://display.companyX.com/rest/banner?l_id=A000-0000-0000000-000000-796-0-0-0&k=A77K_fakfhaskfhkjshfkjo=kafkjafk",
"http://display.companyX.com/rest/banner?l_id=A000-0000-0000000-000000-051-0-0-0&k=A77K_fakfhaskfhkjshfkjo=kafkjafk",
"http://display.companyX.com/rest/banner?l_id=A000-0000-0000000-000000-056-0-0-0&k=A77K_fakfhaskfhkjshfkjo=kafkjafk",
]

从另一个答案中，我能够获取数组中唯一的第五个代码:

var unique = ['791','246','796', '051','056']

然后我尝试执行此操作以获取唯一的 URL 并将其推送到空数组，但没有成功。

var uniqueUrls = []
for(i=0; i < unique.length; i++){
  for(j=0; j< urls.length; j++){
    if(urls[j].indexOf(unique[i])){
      uniqueUrls.push(urls[j]);
      break;
    }
  }
}

有人可以帮我解决这个问题吗？我在 for 循环中做错了什么吗？或者是否有更好的方法从 URL 数组中获取唯一的 URL，而不使用双 for 循环？

更新

忘记提及其他数字代码并不总是“零”，它们可以是任何随机数，但我仍然有兴趣根据第五个代码获取唯一的网址。

Answer 1

您可以使用 ES6 Set 和数组扩展来获取唯一值:

const getUnique = (urls) => [...new Set(urls.map((url) => url.match(/\/banner\?l_id=(?:\w+-){4}(\w+)/)[1]))];

var urls = [
  "http://display.companyX.com/rest/banner?l_id=A000-0000-0000000-000000-791-0-0-0&k=A77K_fakfhaskfhkjshfkjo=kafkjafk",
  "http://display.companyX.com/rest/banner?l_id=A000-0000-0000000-000000-791-0-0-0&k=A77K_fakfhaskfhkjshfkjo=kafkjafk",
  "http://display.companyX.com/rest/banner?l_id=A000-0000-0000000-000000-246-0-0-0&k=A77K_fakfhaskfhkjshfkjo=kafkjafk",
  "http://display.companyX.com/rest/banner?l_id=A000-0000-0000000-000000-246-0-0-0&k=A77K_fakfhaskfhkjshfkjo=kafkjafk",
  "http://display.companyX.com/rest/banner?l_id=A000-0000-0000000-000000-796-0-0-0&k=A77K_fakfhaskfhkjshfkjo=kafkjafk",
  "http://display.companyX.com/rest/banner?l_id=A000-0000-0000000-000000-796-0-0-0&k=A77K_fakfhaskfhkjshfkjo=kafkjafk",
  "http://display.companyX.com/rest/banner?l_id=A000-0000-0000000-000000-051-0-0-0&k=A77K_fakfhaskfhkjshfkjo=kafkjafk",
  "http://display.companyX.com/rest/banner?l_id=A000-0000-0000000-000000-051-0-0-0&k=A77K_fakfhaskfhkjshfkjo=kafkjafk",
  "http://display.companyX.com/rest/banner?l_id=A000-0000-0000000-000000-056-0-0-0&k=A77K_fakfhaskfhkjshfkjo=kafkjafk",
  "http://display.companyX.com/rest/banner?l_id=A000-0000-0000000-000000-056-0-0-0&k=A77K_fakfhaskfhkjshfkjo=kafkjafk",
];
  
console.log(getUnique(urls));

如果您无法使用 ES6，请使用带有哈希对象的reduce来检查唯一性:

function getUnique(urls) {
  var hash = {};
  
  return urls.reduce(function(arr, url)  {
    var id = url.match(/\/banner\?l_id=(?:\w+-){4}(\w+)/)[1];
    
    if(!hash[id]) {
      arr.push(id);
      
      hash[id] = true;
    }
    
    return arr;
  }, []);
}

var urls = [
  "http://display.companyX.com/rest/banner?l_id=A000-0000-0000000-000000-791-0-0-0&k=A77K_fakfhaskfhkjshfkjo=kafkjafk",
  "http://display.companyX.com/rest/banner?l_id=A000-0000-0000000-000000-791-0-0-0&k=A77K_fakfhaskfhkjshfkjo=kafkjafk",
  "http://display.companyX.com/rest/banner?l_id=A000-0000-0000000-000000-246-0-0-0&k=A77K_fakfhaskfhkjshfkjo=kafkjafk",
  "http://display.companyX.com/rest/banner?l_id=A000-0000-0000000-000000-246-0-0-0&k=A77K_fakfhaskfhkjshfkjo=kafkjafk",
  "http://display.companyX.com/rest/banner?l_id=A000-0000-0000000-000000-796-0-0-0&k=A77K_fakfhaskfhkjshfkjo=kafkjafk",
  "http://display.companyX.com/rest/banner?l_id=A000-0000-0000000-000000-796-0-0-0&k=A77K_fakfhaskfhkjshfkjo=kafkjafk",
  "http://display.companyX.com/rest/banner?l_id=A000-0000-0000000-000000-051-0-0-0&k=A77K_fakfhaskfhkjshfkjo=kafkjafk",
  "http://display.companyX.com/rest/banner?l_id=A000-0000-0000000-000000-051-0-0-0&k=A77K_fakfhaskfhkjshfkjo=kafkjafk",
  "http://display.companyX.com/rest/banner?l_id=A000-0000-0000000-000000-056-0-0-0&k=A77K_fakfhaskfhkjshfkjo=kafkjafk",
  "http://display.companyX.com/rest/banner?l_id=A000-0000-0000000-000000-056-0-0-0&k=A77K_fakfhaskfhkjshfkjo=kafkjafk",
];
  
console.log(getUnique(urls));