HTML實(shí)現(xiàn)簡(jiǎn)單計(jì)算器附詳細(xì)思路

字號(hào):


    代碼如下:
    <!DOCTYPE html>
    <html>
    <meta name="content-type" content="text/html; charset=UTF-8">
    <head>
    <title>Calculator</title>
    <!--將按鍵內(nèi)容以字符串形式存儲(chǔ)在文字框中當(dāng)按鈕為“=”時(shí),調(diào)用eval方法計(jì)算結(jié)果然后將結(jié)果輸出文字框中-->
    <script type="text/javascript">
    var numresult;
    var str;
    function onclicknum(nums) {
    str = document.getElementById("nummessege");
    str.value = str.value + nums;
    }
    function onclickclear() {
    str = document.getElementById("nummessege");
    str.value = "";
    }
    function onclickresult() {
    str = document.getElementById("nummessege");
    numresult = eval(str.value);
    str.value = numresult;
    }
    </script>
    </head>
    <body bgcolor="affff" >
    <!--定義按鍵表格,每個(gè)按鍵對(duì)應(yīng)一個(gè)事件觸發(fā)-->
    <table bgColor="#bbff77"
    style="height: 350px; width: 270px">
    <tr>
    <td colspan="4">
    <input type="text" id="nummessege"
    style="height: 90px; width: 350px; font-size: 50px" />
    </td>
    </tr>
    <tr>
    <td>
    <input type="button" value="1" id="1" onclick="onclicknum(1)"
    style="height: 70px; width: 90px; font-size: 35px">
    </td>
    <td>
    <input type="button" value="2" id="2" onclick="onclicknum(2)"
    style="height: 70px; width: 90px; font-size: 35px">
    </td>
    <td>
    <input type="button" value="3" id="3" onclick="onclicknum(3)"
    style="height: 70px; width: 90px; font-size: 35px">
    </td>
    <td>
    <input type="button" value="+" id="add" onclick="onclicknum('+')"
    style="height: 70px; width: 90px; font-size: 35px">
    </td>
    </tr>
    <tr>
    <td>
    <input type="button" value="4" id="4" onclick="onclicknum(4)"
    style="height: 70px; width: 90px; font-size: 35px">
    </td>
    <td>
    <input type="button" value="5" id="5" onclick="onclicknum(5)"
    style="height: 70px; width: 90px; font-size: 35px">
    </td>
    <td>
    <input type="button" value="6" id="6" onclick="onclicknum(6)"
    style="height: 70px; width: 90px; font-size: 35px">
    </td>
    <td>
    <input type="button" value="-" id="sub" onclick="onclicknum('-')"
    style="height: 70px; width: 90px; font-size: 35px">
    </td>
    </tr>
    <tr>
    <td>
    <input type="button" value="7" id="7" onclick="onclicknum(7)"
    style="height: 70px; width: 90px; font-size: 35px">
    </td>
    <td>
    <input type="button" value="8" id="8" onclick="onclicknum(8)"
    style="height: 70px; width: 90px; font-size: 35px">
    </td>
    <td>
    <input type="button" value="9" id="9" onclick="onclicknum(9)"
    style="height: 70px; width: 90px; font-size: 35px">
    </td>
    <td>
    <input type="button" value="*" id="mul" onclick="onclicknum('*')"
    style="height: 70px; width: 90px; font-size: 35px">
    </td>
    </tr>
    <tr>
    <td colspan="2">
    <input type="button" value="0" id="0" onclick="onclicknum(0)"
    style="height: 70px; width: 190px; font-size: 35px">
    </td>
    <td>
    <input type="button" value="." id="point" onclick="onclicknum('.')"
    style="height: 70px; width: 90px; font-size: 35px">
    </td>
    <td>
    <input type="button" value="/" id="division"
    onclick="onclicknum('/')"
    style="height: 70px; width: 90px; font-size: 35px">
    </td>
    </tr>
    <tr>
    <td colspan="2">
    <input type="button" value="Del" id="clear"
    onclick="onclickclear()"
    style="height: 70px; width: 190px; font-size: 35px" />
    </td>
    <td colspan="2">
    <input type="button" value="=" id="result"
    onclick="onclickresult()"
    style="height: 70px; width: 190px; font-size: 35px" />
    </td>
    </tr>
    </table>
    </body>
    </html>