javascript - 随机选择没有重复项的数组项而不删除项(JavaScript)

Question

我见过很多关于随机选择数组项而不重复的问题。但是，其中大多数是通过使用拼接方法来回答的。但这会删除项目。

我已经随机选择了我的项目，但它们在重复。在我的两个函数中，我从每个随机选择的项目中选择两个“子项目”。这两个功能不能一起工作，我正在寻找一种方法，可以选择两个不同的随机选择的项目，而不会重复，也不会删除它们。有人能帮帮我吗？

(使用 Adob​​e Edge Animate)

var xml_source = "series.xml";
var initLoadScript = false;

var items = [];
var itemTitle1;
var obj = new Object();
var previousNumber = -1;

loadXML();

function loadXML() {
	$.ajax({
		type: "GET",
		url: xml_source,
		dataType: "xml",
		success: function(xml) {

			$(xml).find('sbs').find('channel').find('item').each(function() {
				items.push($(this));
			});

			itemOne();
			itemTwo();
		}
	});
}

function itemOne(){
	var randomNumber = Math.floor(Math.random()*14);
	var assignItem = randomNumber;
	console.log("random nummer 1: " + assignItem);
	sym.$("TitleText1").html(items[assignItem].find("author_name").text());
	sym.$("Image1").html("<img src='"+items[assignItem].find('media\\:content, content').find('media\\:thumbnail, thumbnail').attr('url')+"' width='145'/>");
}

function itemTwo(){
	var randomNumber = Math.floor(Math.random()*14);
	var assignItem = randomNumber;
	console.log("random nummer 2: " + assignItem);
	sym.$("TitleText2").html(items[assignItem].find("author_name").text());
	sym.$("Image2").html("<img src='"+items[assignItem].find('media\\:content, content').find('media\\:thumbnail, thumbnail').attr('url')+"' width='145'/>");	
}

XML 结构示例:

<?xml version="1.0" encoding="UTF-8" ?>
<sbs version="1.0" xmlns:media="http://search.yahoo.com/mrss/">
 <channel>
  <title>Feed</title>
  <description>Video</description>
  <link>//www.URL.com</link>
  <lastBuildDate>Fri</lastBuildDate>
  <pubDate>Fri</pubDate>
  <ttl>1</ttl>
  
     
  <item>
   <title>title</title>
   <description>aflevering</description>
   <link>//www.google.com</link>
   <guid>//www.google.com</guid>
   <formatname>berg</formatname>
   <pubDate>Wed</pubDate>

    <!-- oEmbed -->
   <oembed>
    <version>1.0</version>
    <type>video</type>
    <provider_name>provider</provider_name>
    <provider_url>http://www.video.nl/url</provider_url>
    <width>10</width>
    <height>10</height>
    <title>title1</title>
    <author_name>author name</author_name>
    <author_url>http://www.google.com/</author_url>
   </oembed>

    <media:content
      url="http://google.com"
      type="text/html"
      medium="document"
      expression="full"
      height="10"
      width="10"
      lang="us">
      <media:title type="plain">title</media:title>
      <media:description type="plain">title descr</media:description>
      <media:thumbnail url="http://google.com/tiger.jpg" width="10" height="10" />
     </media:content>

  </item>

Answer 1

我不太了解您要实现的目标，但这是我一次获得随机元素的一种方式

var letters = ["A", "B", "C", "D", "E", "F", "G", "H", "I", "J", "K", "L", "M", "N"];
var getRandom = (function (array) {
    var notGivenItems = array.map(function (el) {return el;}),
    var getIndex = function () {
      return Math.floor(Math.random() * notGivenItems.length);
    };

    return function () {
        if (notGivenItems.length === 0) {
            return;
        }

        return notGivenItems.splice(getIndex(), 1)[0];
    };
})(letters); // items, in your case

getRandom(); // some letter
getRandom(); // some other letter
...
getRandom(); // different letters until all are given

// if the method is called more times than the array length it'll return undefined

编辑:由于@JLRishe 评论提高了性能