<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd"> <html xmlns="http://www.w3.org/1999/xhtml"> <head> <meta charset="utf-8"> <title>简单的DOM操作-实现简单的运算</title> <script type="text/javascript" language="javascript"> window.onload = function () { //alert("window.onload!!!"); var opNum1 = window.document.getElementById("opNum1"); var opNum2 = window.document.getElementById("opNum2"); //var op = window.document.getElementById("op"); var btnElements = window.document.getElementsByName("operater"); //.getElementsByTagName("input[type=button]"); var btnElementsLength = btnElements.length; for (var i = 0; i < btnElementsLength; i++) { //alert(i); btnElements[i].onclick = function () { //alert(opNum1.value + "_" + opNum2.value + "_" + this.value); operate(opNum1.value, opNum2.value, this.value); } } } function operate(opNum1, opNum2, op) { var result=null; switch (op) { case "+": result = parseFloat(opNum1) + parseFloat(opNum2); break; case "-": result = parseFloat(opNum1) - parseFloat(opNum2); break; case "*": result = parseFloat(opNum1) * parseFloat(opNum2); break; case "https://www.jb51.net/": result = parseFloat(opNum1) / parseFloat(opNum2); break; case "%": result = parseFloat(opNum1) % parseFloat(opNum2); break; default: break; } var resultElement = window.document.getElementById("resultSpan"); resultElement.innerHTML = result; } </script> <style type="text/css"> body{ line-height:30px; font-size:20px; } input[type=button]{ width:50px; } </style> </head> <body> 运算数1：<input type="text" /><br /> 运算数2：<input type="text" /><br /> 选择操作符： <input type="button" value="+" /> <input type="button" value="-" /> <input type="button" value="*" /> <input type="button" value="https://www.jb51.net/" /> <input type="button" value="%" /> <br /> 运算结果为：<span></span><br /> </body> </html>
PS：这里再为大家推荐几款计算工具供大家进一步参考借鉴：
更多关于JavaScript相关内容感兴趣的读者可查看本站专题：《JavaScript操作DOM技巧总结》、《JavaScript替换操作技巧总结》、《javascript编码操作技巧总结》、《JavaScript中json操作技巧总结》、《JavaScript查找算法技巧总结》、《JavaScript错误与调试技巧总结》、《JavaScript数据结构与算法技巧总结》、《JavaScript遍历算法与技巧总结》及《JavaScript数学运算用法总结》