Question

我试图计算用户在html脚本中提供的输入的总薪水。我总是得到一个未定义的总薪酬结果。我尝试从第二个脚本标记中调用calculate_pay函数，但这并没有改变任何内容。我做错了什么？

<!DOCTYPE html>
<head>
<title>Chapter 4 Assignment</title>
<script>



function input_output(netPay)
{

var hoursWorked = prompt("How many hours have you worked?","");
var payRate = prompt ("What is your hourly pay rate?","");
var taxRate = prompt ("What is the tax rate for your state? ex. 11 for 11%","");
var br = "<br>";


document.write("Hours worked: "+hoursWorked+br);
document.write("Pay rate: "+payRate+br);
document.write("Tax rate: "+taxRate+br);
document.write("Total pay: "+netPay+br);
}

function calculate_pay(hoursWorked,payRate,taxRate)
{
var taxRate = taxRate/100;
var grossPay = (hoursWorked*taxRate);
var netPay = grossPay - (taxRate * grossPay);
return netPay;
}

</script>
</head>
<body>
<script>

input_output();


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

我尝试在input_output中调用calculate_pay函数，如下所示：

function input_output(netPay)
{

var hoursWorked = prompt("How many hours have you worked?","");
var payRate = prompt ("What is your hourly pay rate?","");
var taxRate = prompt ("What is the tax rate for your state? ex. 11 for 11%","");
var br = "<br>";

calculate_pay();

document.write("Hours worked: "+hoursWorked+br);
document.write("Pay rate: "+payRate+br);
document.write("Tax rate: "+taxRate+br);
document.write("Total pay: "+netPay+br);
}

除了在第二个脚本标签中同时调用它，但它仍然返回undefined。

Answer 1

我认为你想要这样的东西：

function input_output() {...} // get rid of the input parameter

在var taxRate行之后添加：

var netPay = calculate_pay(hoursWorked, payRate, taxRate);

Answer 2

您只是调用input_output()功能，该功能会提示用户hoursWorked，payRate和taxRate，但从不计算任何内容。 input_output()，netPay的参数可能放错了位置。您应该调用函数calculate_pay()来实际获得该值。

第一个函数的最后一行应该是

document.write("Total pay: " + calculate_pay(hoursWorked,payRate,taxRate) + br);

但在到达那里之前，您必须注意使用parseFloat将输入值从String转换为Number。也就是说，对于您拥有的每个提示，请执行以下操作：

var hoursWorked = parseFloat(
  prompt("How many hours have you worked?","")
);

无论用户类型始终为String，因此请务必使用Number方法将这些字符串值转换为实际parseFloat()。

来自函数的未定义结果（html脚本）

2 个答案: