JavaScript NaN錯誤循環

我在運行此代碼時收到一個NaN錯誤。我一直在試圖找出爲什麼現在有一段時間，不能爲我的生活。JavaScript NaN錯誤循環

爲了澄清，我試圖接受;

客戶

應付總金額有多少客戶在進入

function Summarise() 
{ 

    ID = prompt("Enter a Customer ID number ", -1) 

    while(ID != -1) 
    { 
     var gasUsed = 0 
     var total = 0 
     gasUsed = prompt("Enter amount of gas used ", "0") 
     ///Standard Rate is used to assist in the calculation of customers in excess of 60 Gas Used 
     StandardRate = 60 * 1.75 

     if(gasUsed <= 60) 
     { 
      total= gasUsed * 2 
      document.write("Customers ID: " + ID) 
      document.write(" has gas usage of " + gasUsed) 
      document.write(" and owes $" + total) 
      document.write("<br/>") 
     } 
     else 
     { 
      total= (gasUsed - 60) * 1.50 + StandardRate 
      document.write("Customers ID: " + ID) 
      document.write(" has gas usage of " + gasUsed) 
      document.write(" and owes $" + total) 
      document.write("<br/>") 

     } 

     var totalowed = total + totalowed 
     var totalcustomers = ++totalcustomers 

     ID = prompt("Enter a Customer ID number ", -1) 

    } 

    document.write("Total amount owed $" + totalowed) 
    document.write("<br/>") 
    document.write("Total Number of customers:" + totalcustomers) 


}

來源

2014-09-29 Ryan Miller

這是因爲你使用了一些變量，它是不確定的，並提供明確的值.. – DeDevelopers 2014-09-29 11:50:27

快速提示：分號不（真的）可選。 – 2014-09-29 11:51:59

我還是非常非常新的JavaScript，你能多解釋一下@ DeDevelopers – 2014-09-29 11:57:50

您需要在循環之前定義這兩個變量：

var totalowed = 0; 
var totalcustomers = 0;

當你分配值給他們，他們最初不確定的，這總是產生問題。

你可以看到下面的工作片段：

function Summarise() { 
 

 
ID = prompt("Enter a Customer ID number ", -1) 
 
var totalowed = 0; 
 
var totalcustomers = 0; 
 
while(ID != -1) 
 
{ 
 
    var gasUsed = 0; 
 
    var total = 0; 
 
    gasUsed = prompt("Enter amount of gas used ", "0"); 
 
    ///Standard Rate is used to assist in the calculation of customers in excess of 60 Gas Used 
 
    StandardRate = 60 * 1.75 
 

 
    if(gasUsed <= 60) 
 
    { 
 
     total = gasUsed * 2; 
 
     document.write("Customers ID: " + ID); 
 
     document.write(" has gas usage of " + gasUsed); 
 
     document.write(" and owes $" + total); 
 
     document.write("<br/>"); 
 
    } 
 
    else 
 
    { 
 
     total= (gasUsed - 60) * 1.50 + StandardRate; 
 
     document.write("Customers ID: " + ID); 
 
     document.write(" has gas usage of " + gasUsed); 
 
     document.write(" and owes $" + total); 
 
     document.write("<br/>"); 
 

 
    } 
 

 
    totalowed = total + totalowed; 
 
    totalcustomers = ++totalcustomers; 
 
    ID = prompt("Enter a Customer ID number ", -1); 
 

 
} 
 

 
document.write("Total amount owed $" + totalowed); 
 
document.write("<br/>") 
 
document.write("Total Number of customers:" + totalcustomers); 
 
} 
 

 
Summarise();

來源

2014-09-29 12:00:24

謝謝你，我明白你的意思。愚蠢的錯誤在我的角色。 – 2014-09-29 12:06:25

我們都有..那裏做過的（： – 2014-09-29 12:18:55

-1

你是不是從提示轉換字符串轉換成整數。在這裏看到：

您可以使用：

ID = parseInt(prompt("Enter a Customer ID number ", -1), 10);

記住要提供一個基數值的parseInt功能的完整性。

How to get numeric value from a prompt box?

來源

2014-09-29 11:51:08 RichieAHB

totalowed和totalcustomers在while循環聲明，因此無法使用外面。您將需要在while循環外定義它們。

來源

2014-09-29 12:00:21 FlorisLang

JavaScript NaN錯誤循環

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