Question

我试图找到用户在弹出窗口中输入的价格的总和并显示总数。我是否必须在输出下添加另一行？我试图在outMsg中添加总数但不成功。感谢

  <!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
<title>Array 02</title>
</head>


  <form action="">

<p>BOOK SALE</p>
<p id="Books"</p>
<input type="button" value="Start" onClick="Books()";>

</form>  
<body>
<script>
    function Books()
    {
            //define variables 
            var  arraySize = 2;
            var bookName = new Array(arraySize);
            var bookPrice = new Array(arraySize);
            var total = 0;

            var outMsg      = "";

            for(var i = 0; i < arraySize; i++)

            {
                    bookName[i] = prompt('Enter Book Name:  ', "");
                    bookPrice[i] = prompt('Enter the Price: ',0);
            }
            for(var i = 0; i < arraySize; i++)

            {
                outMsg = outMsg + bookName[i] + " " + bookPrice[i] + "</br>" + total; // put backslash n (\n) to show on window
                //alert(outMsg)
                document.getElementById("Books").innerHTML = outMsg;

            }
    }
    </script>
</body>
<html>

Answer 1

在循环中，您需要计算total变量，如下所示：

for(var i = 0; i < arraySize; i++)
{
    total += parseFloat(bookPrice[i]);
    // Whatever else you need to do...
}

Answer 2

计算total并使用parseInt（或parseFloat）进行类型转换

    function Books() {
      //define variables 
      var arraySize = 2;
      var bookName = new Array(arraySize);
      var bookPrice = new Array(arraySize);
      var total = 0;

      var outMsg = "";

      for (var i = 0; i < arraySize; i++)

      {
        bookName[i] = prompt('Enter Book Name:  ', "");
        bookPrice[i] = prompt('Enter the Price: ', 0);
        total += parseInt(bookPrice[i]);
      }
      for (var i = 0; i < arraySize; i++)

      {
        outMsg = outMsg + bookName[i] + " " + bookPrice[i] + "</br>" + total + "</br>"; // put backslash n (\n) to show on window
        //alert(outMsg)
        document.getElementById("Books").innerHTML = outMsg;

      }
    }

<!DOCTYPE html>
<html lang="en">

<head>
  <meta charset="UTF-8">
  <title>Array 02</title>
</head>


<form action="">

  <p>BOOK SALE</p>
  <p id="Books" </p>
    <input type="button" value="Start" onClick="Books()" ;>

</form>

<body>
  <script>
  </script>
</body>
<html>

Answer 3

首先，您需要使用parseInt()并在for循环中添加total变量来计算总计。然后你需要计算你想要追加的响应，然后将第二个for循环之外的响应附加到你需要的元素。数组02

  <form action="">

<p>BOOK SALE</p>
<p id="Books"</p>
<input type="button" value="Start" onClick="Books();" >

</form>  
<body>
<script>
    function Books()
    {
            //define variables 
            var  arraySize = 2;
            var bookName = new Array(arraySize);
            var bookPrice = new Array(arraySize);
            var total = 0;

            var outMsg      = "";

            for(var i = 0; i < arraySize; i++)    
            {
                    bookName[i] = prompt('Enter Book Name:  ', "");
                    bookPrice[i] = prompt('Enter the Price: ',0);
                    total += parseInt(bookPrice[i]);
            }
            console.info("TOTAL PRICE:" + total );//this will print in blue color the total price in your console
            for(var i = 0; i < arraySize; i++)    
            {
                outMsg = outMsg + bookName[i] + " " + bookPrice[i] + "</br>" + total; // put backslash n (\n) to show on window
                //alert(outMsg)
                console.info("OutMsg :" + outMsg);// use console.log(),console.info(), console.warn(), instead of the old school alert() along with the browser/firebug console.
                 //You should move this line out of for loop because you only have one element in which you wish to append your output
                //document.getElementById("Books").innerHTML = outMsg;

            }
            document.getElementById("Books").innerHTML = outMsg;
    }
    </script>
</body>
<html>

javascript中输入的总和

3 个答案: