js小练习

js小练习：
<!DOCTYPE html><html><head><meta charset="UTF-8"><title>白云霞'boyfriend</title></head><body><div align="center">

        <form action="" method="post" onsubmit="return avg()">

            <thead>

                <tr ><th colspan=2 style="text-align:center">比赛算分</th></tr>

            </thead>

            <tbody>

                <tr>

                    <td>评委1</td>

                    <!--只能输入数字,能输小数点.-->

                    <td><input onkeyup="if(isNaN(value))execCommand('undo')" onafterpaste="if(isNaN(value))execCommand('undo')" id="score1"></td>

                </tr>

                <tr>

                    <td>评委2</td>

                    <td><input onkeyup="if(isNaN(value))execCommand('undo')" onafterpaste="if(isNaN(value))execCommand('undo')" id="score2"></td>

                </tr>

                <tr>

                    <td>评委3</td>

                    <td><input onkeyup="if(isNaN(value))execCommand('undo')" onafterpaste="if(isNaN(value))execCommand('undo')" id="score3"></td>

                </tr>

                <tr>

                    <td>评委4</td>

                    <td><input onkeyup="if(isNaN(value))execCommand('undo')" onafterpaste="if(isNaN(value))execCommand('undo')" id="score4"></td>

                </tr>

                <tr>

                    <td>评委5</td>

                    <td><input onkeyup="if(isNaN(value))execCommand('undo')" onafterpaste="if(isNaN(value))execCommand('undo')" id="score5"></td>

                </tr>

                <tr>

                    <td>评委6</td>

                    <td><input onkeyup="if(isNaN(value))execCommand('undo')" onafterpaste="if(isNaN(value))execCommand('undo')" id="score6"></td>

                </tr>

            </tbody>            

            <div>

                <button type="submit" >确认</button>

                <button type="reset" >重填</button>

            </div>

        </form></div><script type="text/javascript">function avg() {

    var score1 = document.getElementById("score1");

    var score2 = document.getElementById("score2");

    var score3 = document.getElementById("score3");

    var score4 = document.getElementById("score4");

    var score5 = document.getElementById("score5");

    var score6 = document.getElementById("score6");

 

    var s1= parseFloat(score1.value);//强行转换为Float型

    var s2= parseFloat(score2.value);

    var s3= parseFloat(score3.value);

    var s4= parseFloat(score4.value);

    var s5= parseFloat(score5.value);

    var s6= parseFloat(score6.value);

 

    var score=new Array();

    score[1]=s1;

    score[2]=s2;

    score[3]=s3;

    score[4]=s4;

    score[5]=s5;

    score[6]=s6;

    

    var min=s1;

    var max=s1;    

    for(var i=1;i<=6;i++){

        if(min>score[i]){

            min=score[i];

        }

    }

    //alert(min);

    for(var i=1;i<=6;i++){

        if(max<score[i]){

            max=score[i];

        }

    }

    //alert(max);

    var count=0;

    for(var i=1;i<=6;i++){

        count=count+score[i];

    }    

    //alert(count);

    var count1=count-min-max;

    //alert(count1);

    var scoreavg=count1/4;

    //alert(scoreavg);    alert("计算平均得分为" + scoreavg.toFixed(2));//保留两位小数  }</script></body></html>
运行截图：