Question

制作一个简单的JavaScript程序，根据年龄和婚姻状况对某些保险括号下的用户进行分类。以下程序有效，但是当我测试程序时，我无法让程序正确区分3级和4级保险。我是javascript的新手所以请原谅如果我有些傻话。

<html xmlns="http://www.w3.org/1999/xhtml">
<head>

       <meta http-equiv="content-type" content="text/html; charset=iso-8859-1" />
<title> Insurance Program </title>

<script type = "text/javascript">

function insurance(form)
{

var fname = form.firstname.value;
var sname = form.surname.value;
var age = form.age.value;
var insurance;

var marital = form.maritalstatus.value;

document.write(marital);

if (marital = 2 && age >= 30)
{
insurance = "Grade 1";
}

else if (marital = 1 && age > 30)
{
insurance = "Grade 2";
}

else if (marital = 2 && age < 30)
{
insurance = "Grade 3";
}

else if (marital = 1 && age < 30)
{
insurance = "Grade 4";
}

document.write("Thank you " + fname + " " + sname + "<br>");
document.write("You belong to " + insurance + " Insurance");

}

</script>


</head>

<body>

<h4> Insurance Program </h4>

<form>
Enter your first-name : <input type = "text" name="firstname"> 
Enter your surname : <input type = "text" name="surname"> <br>
Enter your age: <input type = "text" name="age"> <br>
Select your current marital status
<Select id ="maritalstatus" name = "maritalstatus">
<option value = "1"> Single </option>
<option value = "2"> Married </option>
</Select>


<input type = "submit" value = "submit" onclick="insurance(this.form)">
</form>


</body>
</html>

Answer 1

首先，当您使用=时，您正在使用===。示例：

if (martial === 2 && age >= 30)

martial = 2和martial = 1总是如此，所以最后两个ifs是相同的。

参考：=是assignment operator，==和===是comparison operators。

JSFiddle：

if (parseInt(marital, 10) === 2 && parseInt(age, 10) >= 30) {
    ins = "Grade 1";
}
else if (parseInt(marital, 10) === 1 && parseInt(age, 10) >= 30) {
    ins = "Grade 2";
}
else if (parseInt(marital, 10) === 2 && parseInt(age, 10) < 30) {
    ins = "Grade 3";
}
else if (parseInt(marital, 10) === 1 && parseInt(age, 10) < 30) {
    ins = "Grade 4";
}

Answer 2

你的问题是每一行看起来像这样：

martial = 1 && ...

marital = 1将marital设置为1。你想比较 marital到1，所以请使用双等号：

martial == 1 && ...

Answer 3

您在=个操作数中误用了if符号，如果您需要比较值，请使用==或===（用于严格类型检查）

Answer 4

你的条件应该是'=='

martial = 2＆amp;＆amp;年龄> = 30

martial == 2＆amp;＆amp;年龄> = 30

因为=是赋值运算符，==是比较。

Javascript：保险计划

4 个答案: