我正在創(chuàng)建一個(gè)導(dǎo)航列表，每當(dāng)將新的部分元素添加到頁(yè)面時(shí)，該列表就會(huì)動(dòng)態(tài)填充。我首先創(chuàng)建了一個(gè)空數(shù)組，其目的是通過(guò)對(duì)其應(yīng)用 forLoop 來(lái)連續(xù)接收頁(yè)面上添加的內(nèi)容。這是 JavaScript 代碼    var list= document.getElementById('navbar__list'); let myArray= []; //Create an empty arrayfor( let i=0; i<=myArray.length; i++){  var triggerSection= document.getElementById('section'+(1+i)); //Call section elements one by one with id=section(1+i)  myArray.push(triggerSection); //push elements to create an array that includes all sections on the page  var sectionName= myArray[i].getAttribute('data-nav'); //Call data-nav value for each item  const newItem= document.createElement('Li'); //create li elemnt inside the document object  newItem.textContent= sectionName; //pass the data-nav value as a text to the li element  newItem.setAttribute('id','item'+(1+i));  list.appendChild(newItem); //pass the li element to the  unordered list}HTML 代碼<ul id="navbar__list">      </ul><section id="section1" data-nav="Section 1" class="your-active-class"><section id="section2" data-nav="Section 2"><section id="section3" data-nav="Section 3">問(wèn)題是，當(dāng)設(shè)置如上所示的 for 循環(huán)的結(jié)束條件時(shí)，它會(huì)在數(shù)組末尾添加一個(gè)值為 (null) 的額外元素，并且控制臺(tái)會(huì)生成該錯(cuò)誤“ Uncaught TypeError: Cannot read property 'getAttribute'為空”當(dāng)刪除等號(hào)以使結(jié)束條件如下 (i<myArray.length) 時(shí)，不再顯示錯(cuò)誤，但創(chuàng)建的 (myArray) 返回空數(shù)組，導(dǎo)航欄上依次不顯示任何項(xiàng)目在網(wǎng)頁(yè)上。