Question

如何在刷新时将阵列中的项目重复多次停止。

我尝试过拼接，但它不起作用，也许我做错了？

<script>
      var r_text = new Array();
      
      //Change the local links to server links
      r_text[0] = '<a href="http://bitbulb.io/posts/9">Calculator</a>';
      r_text[1] = '<a href="http://bitbulb.io/posts/8">Todo List</a>';
      r_text[2] = '<a href="http://bitbulb.io/posts/10">Number Sorting Application</a>';
      r_text[3] = '<a href="http://bitbulb.io/posts/11">Text Encryption / Decryption Application</a>';
      r_text[4] = '<a href="http://bitbulb.io/posts/12">Alarm Clock</a>';

      var i = Math.floor(r_text.length * Math.random());
      	document.write(r_text[i]);
      		
    </script>

Answer 1

解决此问题的方法之一是使用localStorage并保存所有显示的链接。页面刷新后，您可以通过键和过滤器链接从localStorage获取值。因此，您只能获得未显示的链接

var key = 'ids';
var arr = [
    '<a href="http://bitbulb.io/posts/9">Calculator</a>',
  '<a href="http://bitbulb.io/posts/8">Todo List</a>',
  '<a href="http://bitbulb.io/posts/10">Number Sorting Application</a>',
  '<a href="http://bitbulb.io/posts/11">Text Encryption / Decryption Application</a>',
  '<a href="http://bitbulb.io/posts/12">Alarm Clock</a>'
];

start(arr, key);

function start(arr, key){
  var showedLinks = getFromStorage(key);
  var len = arr.length;

  if (showedLinks.length == len){
    saveToStorage([], key);
    showedLinks = [];
  }

  var unshowedLinks = arr.filter( link => showedLinks.indexOf(link) === -1);
  var randomIndex = getRandom(unshowedLinks.length);
  var randomLink = unshowedLinks[randomIndex];

  var elem = document.createElement('div');
  elem.innerHTML = randomLink;
  document.body.appendChild(elem);

  showedLinks.push(randomLink);
  saveToStorage(showedLinks, key);  
}

function getRandom(len){
    return Math.floor(len * Math.random());
}

function saveToStorage(data, key){
    window.localStorage.setItem(key, JSON.stringify(data));
}

function getFromStorage(key){
  var data = window.localStorage.getItem(key);
  return data? JSON.parse(data): [];
}

如何在显示项目后停止数组中的项目重复

1 个答案: