爲什麼我的計算不起作用？

我想解決變量x。我想我的D變量有問題。 D變量應該將每個輸入的w加起來。例如，如果有三個輸入，則爲D = w[0]+w[1]+w[2];如果有兩個輸入，則爲D = w[0]+w[1]。具有實數值，與goal_grade = 90.0，exam_weight = 20，4個額外的類別，w[1] = 10，p[1] = 100，w[2] = 20，p[2] = 95.98，w[3] = 30，p[3] = 95.47，和w[4] = 20，p[4] = 96.47。 .. x應該等於約62，而是我得到一些巨大的數字。爲什麼我的計算不起作用？

<html> 
 

 
<head> 
 
    <script type='text/javascript'> 
 
    var w = []; 
 
    var p = []; 
 
    var C = 0; 
 
    var D = 0; 
 

 
    function addFields() { 
 
     // Number of inputs to create 
 
     var number = document.getElementById("category_weight").value; 
 
     // Container <div> where dynamic content will be placed 
 
     var container = document.getElementById("container"); 
 
     // Clear previous contents of the container 
 
     while (container.hasChildNodes()) { 
 
     container.removeChild(container.lastChild); 
 
     } 
 
     for (i = 0; i < number; i++) { 
 
     // create a row element to contain each pair 
 
     var row = document.createElement("div"); 
 
     row.id = 'row' + i 
 

 
     row.appendChild(document.createTextNode("Category " + (i + 1) + " weight: ")); 
 
     var weight_input = document.createElement("input"); 
 
     weight_input.type = "number"; 
 
     weight_input.name = "weight"; 
 
     row.appendChild(weight_input); 
 

 
     row.appendChild(document.createTextNode("Category " + (i + 1) + " percentage: ")); 
 
     var percentage_input = document.createElement("input"); 
 
     percentage_input.type = "number"; 
 
     percentage_input.name = "percentage"; 
 
     row.appendChild(percentage_input); 
 

 
     // append inputs to row instead of container, then append each row to container 
 
     container.appendChild(row); 
 
     } 
 
    } 
 

 
    function weighted() { 
 

 
     var container = document.getElementById("container"); 
 
     var rows = container.children; 
 
     for (var i = 0; i < rows.length; i++) { 
 
     var row = rows[i]; 
 
     w[i] = row.children[0].value; // or row.querySelectorAll('[name=weight]').value; 
 
     p[i] = row.children[1].value; 
 

 
     } 
 

 
     for (var i = 0; i < rows.length; i++) { 
 
     // You can do as much calculation here with w[i] & p[i] 
 
     C += w[i] * p[i]; 
 
     D += w[i]; 
 

 
     } 
 
     console.log(C); 
 
     console.log(D); 
 

 
     var x = ""; 
 
     var A = parseFloat(document.getElementById("goal_grade").value); 
 
     var B = parseFloat(document.getElementById("exam_weight").value); 
 

 

 
     x = (A * (D + B) - C)/B; 
 

 
     if (x <= 0) { 
 
     x = 0; 
 
     } 
 

 
     document.getElementById("result").innerHTML = x; 
 

 
    } 
 
    </script> 
 
</head> 
 

 
<body> 
 
    <span>What final percentage in the class are you trying to reach or stay   above?</span> 
 
    <input type="number" id="goal_grade" name="goal_grade" /> 
 

 
    <br> 
 
    <br> 
 

 
    <span>What percent is the final exam weighted?</span> 
 
    <input type="number" id="exam_weight" name="exam_weight" /> 
 

 
    <br> 
 
    <br> 
 

 
    <span>How many extra weighted categories are there?</span> 
 
    <input type="number" id="category_weight" name="category_weight" value=""> <br /> 
 
    <button type="button" onclick="addFields()">Submit </button> 
 
    <div id="container"></div> 
 

 
    <br> 
 
    <br> 
 

 
    <input type="button" value="Calculate" onclick="weighted()" /> 
 

 
    <br> 
 
    <br> 
 

 
    <span>You will need to get <p id="result" name="r1"> </p> points out of the ... <p id="totpoints" name="tot_points"> </p> points possible on the final" 
 
</span> 
 

 
</body> 
 

 
</html>

來源

2017-04-24 Denizhan Yigitbas

提示：爲了改善問題，請嘗試將問題隔離爲只有JavaScript函數無法正常工作（例如，用示例javascript值替換輸入字段）。 –

其他提示：嘗試給出更詳細的問題描述以及你試圖解決的問題 –

這是否更好？ –

只要改變

C += w[i] * p[i]; 
    D += w[i];

與

C += parseFloat(w[i] * p[i]); 
    D += parseFloat(w[i]);

，你是好。

來源

2017-04-24 22:46:50

偉大的工作！ –

Sevindim :)但是你應該重新考慮你如何處理變量，因爲當你再次點擊按鈕時，函數會再次被調用，從而導致整個計算錯誤。試試看，你會看到。 –

Vayyyy ... Tesekkurler :) !!我只是測試它，明白你現在在說什麼。有沒有快速的方法來解決這個問題？ –

爲什麼我的計算不起作用？

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