用JavaScript实现简单计算器网页，如果点击运行没反应，刷新一下即可。
<style> /* 主体 */ .counter{ width: 396px; height: 486px; background-color: #F2F2F2; border: 1px solid #C2C3C6; margin: 50px auto; } /* 显示框 */ #box { height: 70px; width: 336px; background-color: #323232; border: none; margin: 40px 25px 32px 25px; font: 700 40px/70px "微软雅黑"; color: #ffffff; padding-right: 10px; } /* 功能区 */ .funct { padding: 0 20px; position: relative; } /* 按钮样式 */ .funct input { height: 40px; width: 60px; margin: 10px 10px; font: 400 20px/40px "微软雅黑"; } /* 清除按钮样式 */ .funct #res { width: 150px; } /* + - = . 按钮浮动 */ #add, #reduce, #round, #sum { position: absolute; right: 0px; bottom: 0px; } /* 减号位置 */ #reduce { right: 30px; top: 60px; } /* 加号位置 */ #add { right: 30px; top: 120px; } /* 等于号位置 */ #sum { height: 100px; right: 30px; bottom: 0px; } /* 小数点位置 */ #round { right: 120px; bottom: 0px; } /* 0 */ #zero { width: 150px; } /* 数字区 */ .numb { width: 280px; } </style> <script> window.onload = function(){ // 数据容器 var left = 0; //被除数 var right = 0; //除数 var sum = 0; //和 var numb = 0; //此变量用来限制点的输入 // 获取id并返回 function $(id){ return document.getElementById(id); } // 运算函数 function operation(id){ if( $("box").value != "0"){ if(left == 0) { $("box").value = $("box").value + $(id).value; left = parseFloat($("box").value); } } //numb 转为number类型 让点可以再输入一次 numb = 0; } // 数字盘函数 function figure(id){ // 判断被除数是否有值 if(left == 0) { // 改变value默认值 if ($("box").value === "0" ) { $("box").value = $(id).value; }else{ $("box").value = $("box").value + $(id).value; } }else{ $("box").value = $("box").value + $(id).value; var str = $("box").value; var num = ""; // 获取第二次输入的数字 for (var i = 0; i < str.length; i++) { // 判断加减乘除 if(str[i]== "+"){ for (var j = i + 1; j < str.length; j++) { num+=str[j]; }; right = parseFloat(num); }else if(str[i]== "-"){ for (var j = i + 1; j < str.length; j++) { num+=str[j]; }; right = parseFloat(num); } else if(str[i]== "*"){ for (var j = i + 1; j < str.length; j++) { num+=str[j]; }; right = parseFloat(num); } else if(str[i]== "/"){ for (var j = i + 1; j < str.length; j++) { num+=str[j]; }; right = parseFloat(num); } }; } // 清空所有数据 if(sum != 0){ left = 0; right = 0; sum = 0; numb = 0; $("box").value = $(id).value; } } // 数字键盘区 $("one").onclick = function(){ figure("one"); } $("two").onclick = function(){ figure("two"); } $("three").onclick = function(){ figure("three"); } $("four").onclick = function(){ figure("four"); } $("five").onclick = function(){ figure("five"); } $("six").onclick = function(){ figure("six"); } $("seven").onclick = function(){ figure("seven"); } $("eight").onclick = function(){ figure("eight"); } $("nine").onclick = function(){ figure("nine"); } $("zero").onclick = function(){ figure("zero"); } // 数字键盘区 //功能区 // 加 $("add").onclick = function(){ operation("add"); } //减 $("reduce").onclick = function(){ operation("reduce"); } // 乘 $("ride").onclick = function(){ operation("ride"); } // 除 $("division").onclick = function(){ operation("division"); } // 点 $("round").onclick = function(){ // 限制点的输入 if(numb === 0 && sum == 0){ //numb值等于0 类型等于number $("box").value = $("box").value + $("round").value; numb = ($("box").value); //numb赋值为字符串 } } // 清除 $("res").onclick = function(){ if($("box").value != "0") { left = 0; right = 0; sum = 0; numb = 0; $("box").value = "0"; } } // 求和 $("sum").onclick = function(){ var symbol = ""; if(left != 0 && right != 0){ for (var i = 0; i < $("box").value.length; i ++ ) { symbol = $("box").value[i]; if(symbol == "+"){ sum = left + right; $("box").value = sum; }else if(symbol == "-"){ sum = left - right; $("box").value = sum; } else if(symbol == "*"){ sum = left * right; $("box").value = sum; } else if(symbol == "/"){ sum = left / right; $("box").value = sum; } }; } } } // 功能区 </script> </head> <body> </div> <div class="counter"> <input type="text" id="box" style="text-align:right" readOnly="true" value="0"> <div class="funct"> <input type="reset" id="res" value="C"> <input type="button" id="division" value="/"> <input type="button" id="ride" value="*"> <input type="button" id="add" value="+"> <input type="button" id="reduce" value="-"> <input type="button" id="round" value="."> <input type="button" id="sum" value="="> <div class="numb"> <input type="button" id="one" value="1"> <input type="button" id="two" value="2"> <input type="button" id="three" value="3"> <input type="button" id="four" value="4"> <input type="button" id="five" value="5"> <input type="button" id="six" value="6"> <input type="button" id="seven" value="7"> <input type="button" id="eight" value="8"> <input type="button" id="nine" value="9"> <input type="button" id="zero" value="0"> </div> </div> </div> </body>
