限制数据列表显示的总条目

使用一些现代的javascript和html，您可以执行以下 *** 作。

这是文档：

<template id="resultstemplate">    <option>Ray0</option>    <option>Ray1</option>    <option>Ray2</option>    <option>Ray3</option>    <option>Ray01</option>    <option>Ray11</option>    <option>Ray21</option>    <option>Ray31</option>    <option>Ray02</option>    <option>Ray12</option>    <option>Ray22</option>    <option>Ray32</option>    <option>Ray012</option>    <option>Ray112</option>    <option>Ray212</option>    <option>Ray312</option>    <option>Ray03</option>    <option>Ray13</option>    <option>Ray23</option>    <option>Ray33</option>    <option>Ray013</option>    <option>Ray113</option>    <option>Ray213</option>    <option>Ray313</option>    <option>Ray023</option>    <option>Ray123</option>    <option>Ray223</option>    <option>Ray323</option>    <option>Ray0123</option>    <option>Ray1123</option>    <option>Ray2123</option>    <option>Ray3123</option></template><input type="text" name="search" id="search"  placeholder="type 'r'" list="searchresults" autocomplete="off" /><datalist id="searchresults"></datalist>

这是js：

var search = document.querySelector('#search');var results = document.querySelector('#searchresults');var templateContent = document.querySelector('#resultstemplate').content;search.addEventListener('keyup', function handler(event) {    while (results.children.length) results.removeChild(results.firstChild);    var inputVal = new RegExp(search.value.trim(), 'i');    var clonedOptions = templateContent.cloneNode(true);    var set = Array.prototype.reduce.call(clonedOptions.children, function searchFilter(frag, el) {        if (inputVal.test(el.textContent) && frag.children.length < 5) frag.appendChild(el);        return frag;    }, document.createdocumentFragment());    results.appendChild(set);});