我的提示似乎不起作用

Question

我似乎无法让我的提示出现在此代码中，以完成我必须为我的课程做的作业。 它应该显示最后的奖励积分数量，但是一旦我向JS添加其他提示和警报，都不会显示任何提示。 有什么建议吗？

var numCoffees, awardPoints;

    numCoffees = prompt("How many coffees have you purchased?");
    if (numCoffees == 0)
      {awardPoints = 0;}

    if (numCoffees == 1)
      {awardPoints = 2;}

    if (numCoffees == 2)
      {awardPoints = 5;}

    if (numCoffees == 3)
      {awardPoints = 9;}

    if (numCoffees > 3)
      {awardPoints = ((9+2)*(numCoffees-3));}

  /*Determine Preferred Customer status*/

 var PreferredCustomer; 

    PreferredCustomer = prompt("Please say "yes" or "no" to indicate if you are a preferred customer.");
    if (PreferredCustomer == "yes")
      {awardPoints = awardPoints*2;}

  /*Display award points*/

    alert("awardPoints" + award points);

Answer 1

您的报价有问题。 将第一个和最后一个引号更改为单引号：

PreferredCustomer = prompt('Please say "yes" or "no" to indicate if you are a preferred customer.');

或者，您可以转义内部引号：

PreferredCustomer = prompt("Please say \"yes\" or \"no\" to indicate if you are a preferred customer.");

并且，由于kakamg0的注释，修复了最后一行：

alert("awardPoints" + awardPoints);

Answer 2

看起来这里主要有一些语法问题。 逻辑上是代码被编写。 它的编写方式有点错误

正如其他人指出的那样：引用是错误的

• 在用双引号组成的字符串中包含双引号将在配对的第一个双引号处结束字符串语句。

• 警报框中的奖励积分不是有效变量。 它包含空格且未定义

总体上整理一下代码，结果是：

var numCoffees, awardPoints;

numCoffees = prompt("How many coffees have you purchased?");
if (numCoffees == 0) { awardPoints = 0; } else
if (numCoffees == 1) { awardPoints = 2; } else
if (numCoffees == 2) { awardPoints = 5; } else
if (numCoffees == 3) { awardPoints = 9; } else
if (numCoffees > 3) { awardPoints = ((9 + 2) * (numCoffees - 3));}

/*Determine Preferred Customer status*/

var PreferredCustomer;

PreferredCustomer = prompt("Please say 'yes'or 'no' to indicate if you are a preferred customer.");
if (PreferredCustomer == "yes") {
  awardPoints = awardPoints * 2;
}

/*Display award points*/

alert("awardPoints" + awardPoints);