<!DOCTYPE html><html lang="en"><head><meta charset="UTF-8"><title>3种用tagname和id获取元素的方法</title><style>body{ margin: 0;}ul{ margin: 0; padding: 0; list-style: none;}h1{ margin: 0;}</style></head><body><div class="box" id="box"> <h1 class="box-tit">分类名称</h1> <ul class="box-list" id="box-list"> <li class="box-listI"> <input class="box-listI-input"> <button>保存</button> <button>取消</button> </li> <li class="box-listI"> <input class="box-listI-input"> <button>保存</button> <button>取消</button> </li> <li class="box-listI"> <input class="box-listI-input"> <button>保存</button> <button>取消</button> </li> </ul></div><script>//[1]整体法，先获取所有的元素，再通过ai+-b的方法来算出需要的元素var oList = document.getElementById(‘box-list‘);var aInput = oList.getElementsByTagName(‘input‘);var aBtn =oList.getElementsByTagName(‘button‘);for(var i = 0; i < aBtn.length; i++){ aBtn[i].index = i;}for(var i = 0; i < aInput.length; i++){ //确定按钮 aBtn[2*i].onclick = function(){ aInput[this.index/2].disabled = true; } //取消按钮 aBtn[2*i+1].onclick = function(){ aInput[(this.index-1)/2].disabled = false; aInput[(this.index-1)/2].value = ‘‘; console.log(1); }}//[2]数组法，在全局环境下建立空数组，遇到需要循环的结构时，在循环中获取元素，并放入数组var oList = document.getElementById(‘box-list‘);var aIn = oList.getElementsByTagName(‘li‘);var aInput = [];var aBtnY = [];var aBtnX = [];for(var i = 0; i < aIn.length; i++){ aInput[i] = aIn[i].getElementsByTagName(‘input‘)[0]; aBtnY[i] = aIn[i].getElementsByTagName(‘button‘)[0]; aBtnX[i] = aIn[i].getElementsByTagName(‘button‘)[1]; aBtnY[i].index = aBtnX[i].index = i; //确定按钮 aBtnY[i].onclick = function(){ aInput[this.index].disabled = true; } //取消按钮 aBtnX[i].onclick = function(){ aInput[this.index].disabled = false; aInput[this.index].value = ‘‘; console.log(2); } }//[3]函数法，遇到相同的几组元素时，只操作一组元素，并用函数传参来实现所有的效果var oList = document.getElementById(‘box-list‘);var aIn = oList.getElementsByTagName(‘li‘);function fn(i){ var oInput = aIn[i].getElementsByTagName(‘input‘)[0]; var oBtnY = aIn[i].getElementsByTagName(‘button‘)[0]; var oBtnX = aIn[i].getElementsByTagName(‘button‘)[1]; //确定按钮 oBtnY.onclick = function(){ oInput.disabled = true; } //取消按钮 oBtnX.onclick = function(){ oInput.disabled = false; oInput.value = ‘‘; console.log(3); } }for( var i = 0; i < aIn.length; i++){ fn(i);}</script></body></html>原文：http://www.cnblogs.com/zhaolizhe/p/6953962.html