Question

使用javascript创建页面以创建模块的子总标记到整个模块标记：我想创建一个函数来计算像这样的小计

小计= Log1 * 10/24 + Log2 * 10/24 + ClassTest * 10/50。

我希望它显示小计的值，如果小计小于12，则显示：“圣诞快乐，下学期要努力工作！”否则，显示：“圣诞快乐，继续保持！”但是我＆＃39 ;努力让代码工作，并想知道为什么会这样。

<!DOCTYPE html>
    <html>
    <head>
    <title></title>
    <meta http-equiv="Content-Type" content="text/html; charset=utf-8"/>


<script type="text/javascript" language="JavaScript">

function doSomething(num1,num2,num3,){


  var numb1 = parseInt(document.myform.num1.value);
  var numb2 = parseInt(document.myform.num2.value);
  var numb3 = parseInt(document.myform.num3.value);

 if (isNaN(numb1)) {
    window.alert("Mark 1 is not a valid number!");
    }
  else if (isNaN(numb2)) {
    window.alert("Mark 2 is not a valid number!");
    }
  else if (isNaN(numb3)) {
    window.alert("Mark 3 is not a valid number!");
    }

  else if (numb1 > 100 || numb2 > 100 || numb3 > 100 ) {
    window.alert("Marks must not be higher than 100!");
        return;
    }
  else if (numb1 < 0 || numb2 < 0 || numb3 < 0  ) {
    window.alert("Marks must not be negative!");
        return;
    } 

  //if…else if…else statement
  log1=numb1*10/24;
  log2=numb2*10/24;
  test=numb3*10/50;
  subtotal = log1+log2+test;



  if (subtotal > 12)
  {
  window.alert( subtotal +"Merry Christmas and Work harder next semester!");

  }

  else if (avg <= 12)
  {
  window.alert(subtotal +"Merry Christmas and Keep it up!”);

  }


</script>
</head>
<body bgcolor="white">
<p>Please input your marks and click the button to start:</p>

<form name="myform">
<p> Log 1 Mark :</p>
<input type="text" size="10" name="num1">

<p> Log 2 Mark:</p>
<input type="text" size="10" name="num2">

<p> Class Test Mark:</p>
<input type="text" size="10" name="num3">



<br>

<input type="button" name="mybutton" value="Continue" onclick="doSomething(num1,num2,num3);">
</form>
</body>
</html>

Answer 1

else if (avg <= 12)

您正在测试一个您从未在任何地方定义过的变量。这可能是你的问题吗？

Answer 2

您的代码存在许多编译问题

您同时使用subtotal和average，而average未定义
您的函数接受一些参数但不使用它们
下面是一个固定示例（确保document.myform.num1.value按预期工作

作为提示，只需打开Developer Tools即可发现这些错误

function doSomething() {
    var numb1 = parseInt(document.myform.num1.value);
    var numb2 = parseInt(document.myform.num2.value);
    var numb3 = parseInt(document.myform.num3.value);

    if (isNaN(numb1)) {
        window.alert("Mark 1 is not a valid number!");
        return;
    }
    else if (isNaN(numb2)) {
        window.alert("Mark 2 is not a valid number!");
        return;
    }
    else if (isNaN(numb3)) {
        window.alert("Mark 3 is not a valid number!");
        return;
    }
    else if (numb1 > 100 || numb2 > 100 || numb3 > 100) {
        window.alert("Marks must not be higher than 100!");
        return;
    }
    else if (numb1 < 0 || numb2 < 0 || numb3 < 0) {
        window.alert("Marks must not be negative!");
        return;
    }

    //if…else if…else statement
    var log1 = numb1 * 10 / 24;
    var log2 = numb2 * 10 / 24;
    var test = numb3 * 10 / 50;
    var subtotal = log1 + log2 + test;

    if (subtotal > 12) {
        window.alert(subtotal + "Merry Christmas and Work harder next semester!");
    }
    else if (subtotal <= 12) {
        window.alert(subtotal + "Merry Christmas and Keep it up!”);

    }
}

尝试使用javascript计算模块小计的小计但响应

2 个答案: