问题描述

求 计算器 可以进行连续的加减乘除 这样的代码如何添加 还有如何限制按键数字个数

 <html>    <head>        <title>JiSuanQi</title>        <script>            var oper = """"            var num = 0;            //输入数字            function addNum(n){                var nowNum = myform.num.value;                if(nowNum == ""0""){                myform.num.value = n                }else{                myform.num.value = myform.num.value + n;                }               }            //添加运算符            function setOper(op){                oper = op;                num = myform.num.value*1;            }            function getCount(){                if(oper != """"){                    if(oper == ""+""){                    }else if(oper == ""-""){                    }else if(oper == ""*""){                    }else if(oper == ""/""){                    }else if(oper == ""%""){                    }                }            }        </script>        <style>            #ceng{width:600px;height:650px;background:#323850;}            .jr{background-Image:url('jr.png')}            .mr{background-Image:url('mr.png')}            .ax{background-Image:url('ax.png')}            .fk{background-Image:url('fk.png')}        </style>    </head>    <body bgcolor=""green"">        <center>        <form id=""myform"">        <div id=""ceng"" align=""center""><br><br><font size=""7"">简易计算器</font><br><br>            <table border=""1"" width=""560px"" height=""480px"" align=""center"">                <tr>                    <td colspan=""4"">                        <input id=""num"" type=""text"" onfocus=""blur()"" value=""0""/>                    </td>                </tr>                <tr>                    <td>                        <input id=""bt1"" type=""button"" value=""1"" onclick=""addNum(1)""/>                    </td>                    <td>                        <input id=""bt2"" type=""button"" value=""2"" onclick=""addNum(2)""/>                    </td>                    <td>                        <input id=""bt3"" type=""button"" value=""3"" onclick=""addNum(3)""/>                    </td>                    <td>                        <input id=""bt10"" type=""button"" value=""+"" onclick=""setOper('+')""/>                    </td>                </tr>                <tr>                    <td>                        <input id=""bt4"" type=""button"" value=""4"" onclick=""addNum(4)""/>                    </td>                    <td>                        <input id=""bt5"" type=""button"" value=""5"" onclick=""addNum(5)""/>                    </td>                    <td>                        <input id=""bt6"" type=""button"" value=""6"" onclick=""addNum(6)""/>                    </td>                    <td>                        <input id=""bt11"" type=""button"" value=""-"" onclick=""addNum()""/>                    </td>                </tr>                <tr>                    <td>                        <input id=""bt7"" type=""button"" value=""7"" onclick=""addNum(7)""/>                    </td>                    <td>                        <input id=""bt8"" type=""button"" value=""8"" onclick=""addNum(8)""/>                    </td>                    <td>                        <input id=""bt9"" type=""button"" value=""9"" onclick=""addNum(9)""/>                    </td>                    <td>                        <input id=""bt12"" type=""button"" value=""*"" onclick=""addNum()""/>                    </td>                </tr>                <tr>                    <td>                        <input id=""bt0"" type=""button"" value=""0"" onclick=""addNum(0)""/>                    </td>                    <td>                        <input id=""bt13"" type=""button"" value=""."" onclick=""addNum()""/>                    </td>                    <td>                        <input id=""bt14"" type=""button"" value=""%"" onclick=""addNum(1)""/>                    </td>                    <td>                        <input id=""bt15"" type=""button"" value=""/"" onclick=""addNum()""/>                    </td>                </tr>                <tr>                    <td>                        <input id=""bt16"" type=""button"" value=""C"" onclick=""addNum()""/>                    </td>                    <td>                        <input id=""bt17"" type=""button"" value=""←"" onclick=""addNum()""/>                    </td>                    <td colspan=""2"">                        <input id=""bt18"" type=""button"" value=""="" onclick=""addNum()""/>                    </td>                </tr>            </table>        </div>        </form>        </center>    </body>    <script>        for (var i = 0;i<19 ;i++ )        {        document.getElementById(""bt""+i).style.width=""140px"";        document.getElementById(""bt""+i).style.height=""90px"";        document.getElementById(""bt""+i).style.fontSize=""80px""        document.getElementById(""bt""+i).className= ""mr""//默认状态按键颜色        document.getElementById(""bt""+i).onmouseover = function(){this.className= ""jr""};//匿名函数（鼠标进入事件）        document.getElementById(""bt""+i).onmouseout = function(){this.className= ""mr""};//鼠标移出事件（默认事件）        document.getElementById(""bt""+i).onmousedown = function(){this.className= ""ax""};//鼠标按下事件        document.getElementById(""bt""+i).onmouseup = function(){this.className= ""fk""};//鼠标放开事件        }        document.getElementById(""bt18"").style.width=""286px"";        document.getElementById(""num"").style.width=""580px"";        document.getElementById(""num"").style.height=""90px"";        document.getElementById(""num"").style.fontSize=""70px"";    </script></html>

解决方案

JiSuanQi
<br> var oper = &quot;&quot;<br> var num = 0;<br> //输入数字<br> function addNum(n){<br> var nowNum = myform.num.value;<br> if(nowNum == &quot;0&quot;){<br> myform.num.value = n<br> }else{<br> myform.num.value = myform.num.value + n;<br> }<br><br> }<br> //添加运算符<br> function setOper(op){<br> oper = op;<br> num = myform.num.value*1;<br> }<br> function getCount(){<br> if(oper != &quot;&quot;){<br> if(oper == &quot;+&quot;){</p><pre><code> }else if(oper == &quot;-&quot;){ }else if(oper == &quot;*&quot;){ }else if(oper == &quot;/&quot;){ }else if(oper == &quot;%&quot;){ } } } &lt;/script&gt; &lt;style&gt; #ceng{width:600px;height:650px;background:#323850;} .jr{background-Image:url('jr.png')} .mr{background-Image:url('mr.png')} .ax{background-Image:url('ax.png')} .fk{background-Image:url('fk.png')} &lt;/style&gt;&lt;/head&gt;&lt;body bgcolor=&quot;green&quot;&gt; &lt;center&gt; &lt;form id=&quot;myform&quot;&gt; &lt;div id=&quot;ceng&quot; align=&quot;center&quot;&gt;&lt;br&gt;&lt;br&gt;&lt;font size=&quot;7&quot;&gt;简易计算器&lt;/font&gt;&lt;br&gt;&lt;br&gt; &lt;table border=&quot;1&quot; width=&quot;560px&quot; height=&quot;480px&quot; align=&quot;center&quot;&gt; &lt;tr&gt; &lt;td colspan=&quot;4&quot;&gt; &lt;input id=&quot;num&quot; type=&quot;text&quot; onfocus=&quot;blur()&quot; value=&quot;0&quot;/&gt; &lt;/td&gt; &lt;/tr&gt; &lt;tr&gt; &lt;td&gt; &lt;input id=&quot;bt1&quot; type=&quot;button&quot; value=&quot;1&quot; onclick=&quot;addNum(1)&quot;/&gt; &lt;/td&gt; &lt;td&gt; &lt;input id=&quot;bt2&quot; type=&quot;button&quot; value=&quot;2&quot; onclick=&quot;addNum(2)&quot;/&gt; &lt;/td&gt; &lt;td&gt; &lt;input id=&quot;bt3&quot; type=&quot;button&quot; value=&quot;3&quot; onclick=&quot;addNum(3)&quot;/&gt; &lt;/td&gt; &lt;td&gt; &lt;input id=&quot;bt10&quot; type=&quot;button&quot; value=&quot;+&quot; onclick=&quot;setOper('+')&quot;/&gt; &lt;/td&gt; &lt;/tr&gt; &lt;tr&gt; &lt;td&gt; &lt;input id=&quot;bt4&quot; type=&quot;button&quot; value=&quot;4&quot; onclick=&quot;addNum(4)&quot;/&gt; &lt;/td&gt; &lt;td&gt; &lt;input id=&quot;bt5&quot; type=&quot;button&quot; value=&quot;5&quot; onclick=&quot;addNum(5)&quot;/&gt; &lt;/td&gt; &lt;td&gt; &lt;input id=&quot;bt6&quot; type=&quot;button&quot; value=&quot;6&quot; onclick=&quot;addNum(6)&quot;/&gt; &lt;/td&gt; &lt;td&gt; &lt;input id=&quot;bt11&quot; type=&quot;button&quot; value=&quot;-&quot; onclick=&quot;addNum()&quot;/&gt; &lt;/td&gt; &lt;/tr&gt; &lt;tr&gt; &lt;td&gt; &lt;input id=&quot;bt7&quot; type=&quot;button&quot; value=&quot;7&quot; onclick=&quot;addNum(7)&quot;/&gt; &lt;/td&gt; &lt;td&gt; &lt;input id=&quot;bt8&quot; type=&quot;button&quot; value=&quot;8&quot; onclick=&quot;addNum(8)&quot;/&gt; &lt;/td&gt; &lt;td&gt; &lt;input id=&quot;bt9&quot; type=&quot;button&quot; value=&quot;9&quot; onclick=&quot;addNum(9)&quot;/&gt; &lt;/td&gt; &lt;td&gt; &lt;input id=&quot;bt12&quot; type=&quot;button&quot; value=&quot;*&quot; onclick=&quot;addNum()&quot;/&gt; &lt;/td&gt; &lt;/tr&gt; &lt;tr&gt; &lt;td&gt; &lt;input id=&quot;bt0&quot; type=&quot;button&quot; value=&quot;0&quot; onclick=&quot;addNum(0)&quot;/&gt; &lt;/td&gt; &lt;td&gt; &lt;input id=&quot;bt13&quot; type=&quot;button&quot; value=&quot;.&quot; onclick=&quot;addNum()&quot;/&gt; &lt;/td&gt; &lt;td&gt; &lt;input id=&quot;bt14&quot; type=&quot;button&quot; value=&quot;%&quot; onclick=&quot;addNum(1)&quot;/&gt; &lt;/td&gt; &lt;td&gt; &lt;input id=&quot;bt15&quot; type=&quot;button&quot; value=&quot;/&quot; onclick=&quot;addNum()&quot;/&gt; &lt;/td&gt; &lt;/tr&gt; &lt;tr&gt; &lt;td&gt; &lt;input id=&quot;bt16&quot; type=&quot;button&quot; value=&quot;C&quot; onclick=&quot;addNum()&quot;/&gt; &lt;/td&gt; &lt;td&gt; &lt;input id=&quot;bt17&quot; type=&quot;button&quot; value=&quot;←&quot; onclick=&quot;addNum()&quot;/&gt; &lt;/td&gt; &lt;td colspan=&quot;2&quot;&gt; &lt;input id=&quot;bt18&quot; type=&quot;button&quot; value=&quot;=&quot; onclick=&quot;addNum()&quot;/&gt; &lt;/td&gt; &lt;/tr&gt; &lt;/table&gt; &lt;/div&gt; &lt;/form&gt; &lt;/center&gt;&lt;/body&gt;&lt;script&gt; for (var i = 0;i&lt;19 ;i++ ) { document.getElementById(&quot;bt&quot;+i).style.width=&quot;140px&quot;; document.getElementById(&quot;bt&quot;+i).style.height=&quot;90px&quot;; document.getElementById(&quot;bt&quot;+i).style.fontSize=&quot;80px&quot; document.getElementById(&quot;bt&quot;+i).className= &quot;mr&quot;//默认状态按键颜色 document.getElementById(&quot;bt&quot;+i).onmouseover = function(){this.className= &quot;jr&quot;};//匿名函数（鼠标进入事件） document.getElementById(&quot;bt&quot;+i).onmouseout = function(){this.className= &quot;mr&quot;};//鼠标移出事件（默认事件） document.getElementById(&quot;bt&quot;+i).onmousedown = function(){this.className= &quot;ax&quot;};//鼠标按下事件 document.getElementById(&quot;bt&quot;+i).onmouseup = function(){this.className= &quot;fk&quot;};//鼠标放开事件 } document.getElementById(&quot;bt18&quot;).style.width=&quot;286px&quot;; document.getElementById(&quot;num&quot;).style.width=&quot;580px&quot;; document.getElementById(&quot;num&quot;).style.height=&quot;90px&quot;; document.getElementById(&quot;num&quot;).style.fontSize=&quot;70px&quot;;&lt;/script&gt;</code></pre><p></html></p><pre><code> &lt;html&gt; &lt;head&gt; &lt;title&gt;JiSuanQi&lt;/title&gt; &lt;script&gt; var oper = &quot;&quot; var num = 0; //输入数字 function addNum(n){ var nowNum = myform.num.value; if(nowNum == &quot;0&quot;){ myform.num.value = n }else{ myform.num.value = myform.num.value + n; } } //添加运算符 function setOper(op){ oper = op; num = myform.num.value*1; } function getCount(){ if(oper != &quot;&quot;){ if(oper == &quot;+&quot;){ }else if(oper == &quot;-&quot;){ }else if(oper == &quot;*&quot;){ }else if(oper == &quot;/&quot;){ }else if(oper == &quot;%&quot;){ } } } &lt;/script&gt; &lt;style&gt; #ceng{width:600px;height:650px;background:#323850;} .jr{background-Image:url('jr.png')} .mr{background-Image:url('mr.png')} .ax{background-Image:url('ax.png')} .fk{background-Image:url('fk.png')} &lt;/style&gt; &lt;/head&gt; &lt;body bgcolor=&quot;green&quot;&gt; &lt;center&gt; &lt;form id=&quot;myform&quot;&gt; &lt;div id=&quot;ceng&quot; align=&quot;center&quot;&gt;&lt;br&gt;&lt;br&gt;&lt;font size=&quot;7&quot;&gt;简易计算器&lt;/font&gt;&lt;br&gt;&lt;br&gt; &lt;table border=&quot;1&quot; width=&quot;560px&quot; height=&quot;480px&quot; align=&quot;center&quot;&gt; &lt;tr&gt; &lt;td colspan=&quot;4&quot;&gt; &lt;input id=&quot;num&quot; type=&quot;text&quot; onfocus=&quot;blur()&quot; value=&quot;0&quot;/&gt; &lt;/td&gt; &lt;/tr&gt; &lt;tr&gt; &lt;td&gt; &lt;input id=&quot;bt1&quot; type=&quot;button&quot; value=&quot;1&quot; onclick=&quot;addNum(1)&quot;/&gt; &lt;/td&gt; &lt;td&gt; &lt;input id=&quot;bt2&quot; type=&quot;button&quot; value=&quot;2&quot; onclick=&quot;addNum(2)&quot;/&gt; &lt;/td&gt; &lt;td&gt; &lt;input id=&quot;bt3&quot; type=&quot;button&quot; value=&quot;3&quot; onclick=&quot;addNum(3)&quot;/&gt; &lt;/td&gt; &lt;td&gt; &lt;input id=&quot;bt10&quot; type=&quot;button&quot; value=&quot;+&quot; onclick=&quot;setOper('+')&quot;/&gt; &lt;/td&gt; &lt;/tr&gt; &lt;tr&gt; &lt;td&gt; &lt;input id=&quot;bt4&quot; type=&quot;button&quot; value=&quot;4&quot; onclick=&quot;addNum(4)&quot;/&gt; &lt;/td&gt; &lt;td&gt; &lt;input id=&quot;bt5&quot; type=&quot;button&quot; value=&quot;5&quot; onclick=&quot;addNum(5)&quot;/&gt; &lt;/td&gt; &lt;td&gt; &lt;input id=&quot;bt6&quot; type=&quot;button&quot; value=&quot;6&quot; onclick=&quot;addNum(6)&quot;/&gt; &lt;/td&gt; &lt;td&gt; &lt;input id=&quot;bt11&quot; type=&quot;button&quot; value=&quot;-&quot; onclick=&quot;addNum()&quot;/&gt; &lt;/td&gt; &lt;/tr&gt; &lt;tr&gt; &lt;td&gt; &lt;input id=&quot;bt7&quot; type=&quot;button&quot; value=&quot;7&quot; onclick=&quot;addNum(7)&quot;/&gt; &lt;/td&gt; &lt;td&gt; &lt;input id=&quot;bt8&quot; type=&quot;button&quot; value=&quot;8&quot; onclick=&quot;addNum(8)&quot;/&gt; &lt;/td&gt; &lt;td&gt; &lt;input id=&quot;bt9&quot; type=&quot;button&quot; value=&quot;9&quot; onclick=&quot;addNum(9)&quot;/&gt; &lt;/td&gt; &lt;td&gt; &lt;input id=&quot;bt12&quot; type=&quot;button&quot; value=&quot;*&quot; onclick=&quot;addNum()&quot;/&gt; &lt;/td&gt; &lt;/tr&gt; &lt;tr&gt; &lt;td&gt; &lt;input id=&quot;bt0&quot; type=&quot;button&quot; value=&quot;0&quot; onclick=&quot;addNum(0)&quot;/&gt; &lt;/td&gt; &lt;td&gt; &lt;input id=&quot;bt13&quot; type=&quot;button&quot; value=&quot;.&quot; onclick=&quot;addNum()&quot;/&gt; &lt;/td&gt; &lt;td&gt; &lt;input id=&quot;bt14&quot; type=&quot;button&quot; value=&quot;%&quot; onclick=&quot;addNum(1)&quot;/&gt; &lt;/td&gt; &lt;td&gt; &lt;input id=&quot;bt15&quot; type=&quot;button&quot; value=&quot;/&quot; onclick=&quot;addNum()&quot;/&gt; &lt;/td&gt; &lt;/tr&gt; &lt;tr&gt; &lt;td&gt; &lt;input id=&quot;bt16&quot; type=&quot;button&quot; value=&quot;C&quot; onclick=&quot;addNum()&quot;/&gt; &lt;/td&gt; &lt;td&gt; &lt;input id=&quot;bt17&quot; type=&quot;button&quot; value=&quot;←&quot; onclick=&quot;addNum()&quot;/&gt; &lt;/td&gt; &lt;td colspan=&quot;2&quot;&gt; &lt;input id=&quot;bt18&quot; type=&quot;button&quot; value=&quot;=&quot; onclick=&quot;addNum()&quot;/&gt; &lt;/td&gt; &lt;/tr&gt; &lt;/table&gt; &lt;/div&gt; &lt;/form&gt; &lt;/center&gt; &lt;/body&gt; &lt;script&gt; for (var i = 0;i&lt;19 ;i++ ) { document.getElementById(&quot;bt&quot;+i).style.width=&quot;140px&quot;; document.getElementById(&quot;bt&quot;+i).style.height=&quot;90px&quot;; document.getElementById(&quot;bt&quot;+i).style.fontSize=&quot;80px&quot; document.getElementById(&quot;bt&quot;+i).className= &quot;mr&quot;//默认状态按键颜色 document.getElementById(&quot;bt&quot;+i).onmouseover = function(){this.className= &quot;jr&quot;};//匿名函数（鼠标进入事件） document.getElementById(&quot;bt&quot;+i).onmouseout = function(){this.className= &quot;mr&quot;};//鼠标移出事件（默认事件） document.getElementById(&quot;bt&quot;+i).onmousedown = function(){this.className= &quot;ax&quot;};//鼠标按下事件 document.getElementById(&quot;bt&quot;+i).onmouseup = function(){this.className= &quot;fk&quot;};//鼠标放开事件 } document.getElementById(&quot;bt18&quot;).style.width=&quot;286px&quot;; document.getElementById(&quot;num&quot;).style.width=&quot;580px&quot;; document.getElementById(&quot;num&quot;).style.height=&quot;90px&quot;; document.getElementById(&quot;num&quot;).style.fontSize=&quot;70px&quot;; &lt;/script&gt;&lt;/html&gt;</code></pre> 解决方案二：
JiSuanQi
<br> var oper = &quot;&quot;<br> var num = 0;<br> //输入数字<br> function addNum(n){<br> var nowNum = myform.num.value;<br> if(nowNum == &quot;0&quot;){<br> myform.num.value = n<br> }else{<br> myform.num.value = myform.num.value + n;<br> }<br><br> }<br> //添加运算符<br> function setOper(op){<br> oper = op;<br> num = myform.num.value*1;<br> }<br> function getCount(){<br> if(oper != &quot;&quot;){<br> if(oper == &quot;+&quot;){</p><pre><code> }else if(oper == &quot;-&quot;){ }else if(oper == &quot;*&quot;){ }else if(oper == &quot;/&quot;){ }else if(oper == &quot;%&quot;){ } } } &lt;/script&gt; &lt;style&gt; #ceng{width:600px;height:650px;background:#323850;} .jr{background-Image:url('jr.png')} .mr{background-Image:url('mr.png')} .ax{background-Image:url('ax.png')} .fk{background-Image:url('fk.png')} &lt;/style&gt;&lt;/head&gt;&lt;body bgcolor=&quot;green&quot;&gt; &lt;center&gt; &lt;form id=&quot;myform&quot;&gt; &lt;div id=&quot;ceng&quot; align=&quot;center&quot;&gt;&lt;br&gt;&lt;br&gt;&lt;font size=&quot;7&quot;&gt;简易计算器&lt;/font&gt;&lt;br&gt;&lt;br&gt; &lt;table border=&quot;1&quot; width=&quot;560px&quot; height=&quot;480px&quot; align=&quot;center&quot;&gt; &lt;tr&gt; &lt;td colspan=&quot;4&quot;&gt; &lt;input id=&quot;num&quot; type=&quot;text&quot; onfocus=&quot;blur()&quot; value=&quot;0&quot;/&gt; &lt;/td&gt; &lt;/tr&gt; &lt;tr&gt; &lt;td&gt; &lt;input id=&quot;bt1&quot; type=&quot;button&quot; value=&quot;1&quot; onclick=&quot;addNum(1)&quot;/&gt; &lt;/td&gt; &lt;td&gt; &lt;input id=&quot;bt2&quot; type=&quot;button&quot; value=&quot;2&quot; onclick=&quot;addNum(2)&quot;/&gt; &lt;/td&gt; &lt;td&gt; &lt;input id=&quot;bt3&quot; type=&quot;button&quot; value=&quot;3&quot; onclick=&quot;addNum(3)&quot;/&gt; &lt;/td&gt; &lt;td&gt; &lt;input id=&quot;bt10&quot; type=&quot;button&quot; value=&quot;+&quot; onclick=&quot;setOper('+')&quot;/&gt; &lt;/td&gt; &lt;/tr&gt; &lt;tr&gt; &lt;td&gt; &lt;input id=&quot;bt4&quot; type=&quot;button&quot; value=&quot;4&quot; onclick=&quot;addNum(4)&quot;/&gt; &lt;/td&gt; &lt;td&gt; &lt;input id=&quot;bt5&quot; type=&quot;button&quot; value=&quot;5&quot; onclick=&quot;addNum(5)&quot;/&gt; &lt;/td&gt; &lt;td&gt; &lt;input id=&quot;bt6&quot; type=&quot;button&quot; value=&quot;6&quot; onclick=&quot;addNum(6)&quot;/&gt; &lt;/td&gt; &lt;td&gt; &lt;input id=&quot;bt11&quot; type=&quot;button&quot; value=&quot;-&quot; onclick=&quot;addNum()&quot;/&gt; &lt;/td&gt; &lt;/tr&gt; &lt;tr&gt; &lt;td&gt; &lt;input id=&quot;bt7&quot; type=&quot;button&quot; value=&quot;7&quot; onclick=&quot;addNum(7)&quot;/&gt; &lt;/td&gt; &lt;td&gt; &lt;input id=&quot;bt8&quot; type=&quot;button&quot; value=&quot;8&quot; onclick=&quot;addNum(8)&quot;/&gt; &lt;/td&gt; &lt;td&gt; &lt;input id=&quot;bt9&quot; type=&quot;button&quot; value=&quot;9&quot; onclick=&quot;addNum(9)&quot;/&gt; &lt;/td&gt; &lt;td&gt; &lt;input id=&quot;bt12&quot; type=&quot;button&quot; value=&quot;*&quot; onclick=&quot;addNum()&quot;/&gt; &lt;/td&gt; &lt;/tr&gt; &lt;tr&gt; &lt;td&gt; &lt;input id=&quot;bt0&quot; type=&quot;button&quot; value=&quot;0&quot; onclick=&quot;addNum(0)&quot;/&gt; &lt;/td&gt; &lt;td&gt; &lt;input id=&quot;bt13&quot; type=&quot;button&quot; value=&quot;.&quot; onclick=&quot;addNum()&quot;/&gt; &lt;/td&gt; &lt;td&gt; &lt;input id=&quot;bt14&quot; type=&quot;button&quot; value=&quot;%&quot; onclick=&quot;addNum(1)&quot;/&gt; &lt;/td&gt; &lt;td&gt; &lt;input id=&quot;bt15&quot; type=&quot;button&quot; value=&quot;/&quot; onclick=&quot;addNum()&quot;/&gt; &lt;/td&gt; &lt;/tr&gt; &lt;tr&gt; &lt;td&gt; &lt;input id=&quot;bt16&quot; type=&quot;button&quot; value=&quot;C&quot; onclick=&quot;addNum()&quot;/&gt; &lt;/td&gt; &lt;td&gt; &lt;input id=&quot;bt17&quot; type=&quot;button&quot; value=&quot;←&quot; onclick=&quot;addNum()&quot;/&gt; &lt;/td&gt; &lt;td colspan=&quot;2&quot;&gt; &lt;input id=&quot;bt18&quot; type=&quot;button&quot; value=&quot;=&quot; onclick=&quot;addNum()&quot;/&gt; &lt;/td&gt; &lt;/tr&gt; &lt;/table&gt; &lt;/div&gt; &lt;/form&gt; &lt;/center&gt;&lt;/body&gt;&lt;script&gt; for (var i = 0;i&lt;19 ;i++ ) { document.getElementById(&quot;bt&quot;+i).style.width=&quot;140px&quot;; document.getElementById(&quot;bt&quot;+i).style.height=&quot;90px&quot;; document.getElementById(&quot;bt&quot;+i).style.fontSize=&quot;80px&quot; document.getElementById(&quot;bt&quot;+i).className= &quot;mr&quot;//默认状态按键颜色 document.getElementById(&quot;bt&quot;+i).onmouseover = function(){this.className= &quot;jr&quot;};//匿名函数（鼠标进入事件） document.getElementById(&quot;bt&quot;+i).onmouseout = function(){this.className= &quot;mr&quot;};//鼠标移出事件（默认事件） document.getElementById(&quot;bt&quot;+i).onmousedown = function(){this.className= &quot;ax&quot;};//鼠标按下事件 document.getElementById(&quot;bt&quot;+i).onmouseup = function(){this.className= &quot;fk&quot;};//鼠标放开事件 } document.getElementById(&quot;bt18&quot;).style.width=&quot;286px&quot;; document.getElementById(&quot;num&quot;).style.width=&quot;580px&quot;; document.getElementById(&quot;num&quot;).style.height=&quot;90px&quot;; document.getElementById(&quot;num&quot;).style.fontSize=&quot;70px&quot;;&lt;/script&gt;</code></pre><p></html></p> 解决方案三：
你的代码太多bug了。。
http://www.jb51.net/article/29295.htm