Javascript实现数组中的元素上下移动

h1>学生信息表格

<form class="info" autocomplete="off"> 姓名：<input type="text" class="uname" name="uname" /> 科目<input type="text" class="subject" name="subject" /> 成绩：<input type="text" class="score" name="score" /> <button class="add">录入</button> </form>

姓名	科目	成绩	操作	操作

<script> var data = [{ uname: '张三', subject: 'JavaScript', score: 100 }, { uname: '李四', subject: 'JavaScript', score: 90 }, { uname: '刘五', subject: 'JavaScript', score: 90 }]; var tbody = document.querySelector('tbody'); for (var i = 0; i < data.length; i++) { var tr = document.createElement('tr'); tbody.appendChild(tr); for (var k in data[i]) { var td = document.createElement('td'); td.innerHTML = data[i][k]; tr.appendChild(td); } var td = document.createElement('td'); td.innerHTML = '<a href="javascript:;">删除 </a>'; tr.appendChild(td); var td = document.createElement('td'); td.innerHTML = <button onclick="moveUp(this)">上移</button> <button onclick="moveDown(this)">下移</button> ; tr.appendChild(td); } var uname = document.querySelector('.uname'); var subject = document.querySelector('.subject'); var score = document.querySelector('.score'); var info = document.querySelector('.info'); var tbody = document.querySelector('tbody'); var arr = []; info.addEventListener('submit', function (e) { e.preventDefault(); var obj = { uname: uname.value, subject: subject.value, score: score.value, } arr.push(obj); this.reset(); for (var i = 0; i < arr.length; i++) { var tr = document.createElement('tr'); tr.innerHTML = ${arr[i].uname} ${arr[i].subject} ${arr[i].score} 删除 <button onclick="moveUp(this)">上移</button> <button onclick="moveDown(this)">下移</button> ; } tbody.appendChild(tr); }) var as = document.querySelectorAll('a'); for (var i = 0; i < as.length; i++) { as[i].onclick = function() { tbody.removeChild(this.parentNode.parentNode) } function moveUp(btn) { var row = btn.parentNode.parentNode; var prevRow = row.previousElementSibling; if (prevRow) { row.parentNode.insertBefore(row, prevRow); } else { row.parentNode.appendChild(row); } } } function moveDown(btn) { var row = btn.parentNode.parentNode; var nextRow = row.nextElementSibling; if (nextRow) { row.parentNode.insertBefore(nextRow, row); } else { var firstRow = row.parentNode.firstElementChild; row.parentNode.insertBefore(row, firstRow); } } </script>怎么用数组索引上下移动行