javascript(一)计算器代码生成

在body区：

<table align="center" >
<tr>
<td colspan="4">
    <input id="Text1" type="text" value="" style=" text-align:right;" /></td>
</tr>
<tr>
<td>
    <input id="Button1" type="button" value="1" style="37px; height: 29px;"/></td>
<td><input id="Button2" type="button" value="2"  style="37px; height: 29px;"/></td>
<td><input id="Button3" type="button" value="3"  style="37px; height: 29px;"/></td>
<td><input id="Button4" type="button" value="+"  style="37px; height: 29px;"/></td>
</tr>
<tr>
<td>
    <input id="Button5" type="button" value="4" style="37px; height: 29px;"/></td>
<td><input id="Button6" type="button" value="5"  style="37px; height: 29px;"/></td>
<td><input id="Button7" type="button" value="6"  style="37px; height: 29px;"/></td>
<td><input id="Button8" type="button" value="-"  style="37px; height: 29px;"/></td>
</tr>
<tr>
<td>
    <input id="Button9" type="button" value="7" style="37px; height: 29px;"/></td>
<td><input id="Button10" type="button" value="8"  style="37px; height: 29px;"/></td>
<td><input id="Button11" type="button" value="9"  style="37px; height: 29px;"/></td>
<td><input id="Button12" type="button" value="*"  style="37px; height: 29px;"/></td>
</tr>
<tr>
<td>
    <input id="Button13" type="button" value="0" style="37px; height: 29px;"/></td>
<td><input id="Button14" type="button" value="."  style="37px; height: 29px;"/></td>
<td><input id="Button15" type="button" value="ESC"  style="37px; height: 29px;"/></td>
<td><input id="Button16" type="button" value="/"  style="37px; height: 29px;"/></td>

</tr>
<tr>
 <td colspan="4">
 <input id="Button17" type="button" value="="  style="100%; height: 29px;"/>
</tr>
</table>

脚本区

    <script type="text/javascript">
       
      

        function dd() {
            var v = document.getElementsByTagName("input");
            for (var i = 0; i < v.length; i++) {
                dd = v[i];
                dd.onclick = initEvent;
            }

        }
        var ss;
        var a = 0;
        function initEvent() {
            var v = document.getElementsByTagName("input");
            var s = indexOf(v, this);
            var txt = document.getElementById("Text1");
          
         
            switch (s) {

                case 0: txt.value = ""; break;
                case 1: txt.value = txt.value + "1"; break;
                case 2: txt.value = txt.value + "2"; break;
                case 3: txt.value = txt.value + "3"; break;
                case 4: ss = "+"; a = txt.value; txt.value = ""; break; 
                case 5: txt.value = txt.value +"4"; break;
                case 6: txt.value = txt.value + "5"; break;
                case 7: txt.value = txt.value + "6"; break;
                case 8:  ss = "-"; a = txt.value; txt.value = ""; break;
                case 9: txt.value = txt.value + "7"; break;
                case 10: txt.value = txt.value + "8"; break;
                case 11: txt.value = txt.value + "9"; break;
                case 12: ss = "*"; a = txt.value; txt.value = ""; break;
                case 13: txt.value = txt.value + "0"; break;
                case 14: txt.value = txt.value + "."; ss = "."; break;
               case 15: txt.value =""; break;
                case 16: ss = "/"; a = txt.value; txt.value = ""; break;

                case 17: switch (ss) {
                        case "+": txt.value = parseFloat(a) + parseFloat(txt.value); break;
                        case "-": txt.value = parseFloat(a) - parseFloat(txt.value); break;
                        case "*":  txt.value = parseFloat(a) * parseFloat(txt.value); break;
                        case "/": if (parseFloat(a)> parseFloat(txt.value)) { txt.value = parseFloat(a) / parseFloat(txt.value); ; break; } else { alert("被除数小于除数！不能相除！") }

                    }

            }
           
           
        }
        function indexOf(arr, element) {
            for (var i = 0; i < arr.length; i++) {
                if (arr[i] == element) {
                    return i;
                    return -1;
                }

            }
        }
  
    </script>