以下为引用的内容：
<html><head>
<title>JS Test</title>
<script type="text/javascript">
function MissingValueException (errMsg) {
this.message = errMsg;
this.name="MissingValueException";
}
function doIt() {
try {
if (document.forms[0].fullName.value == '') {
noNameException = new MissingValueException("First name is missing.");
throw noNameException;
} else {
document.forms[0].submit();
}
} catch(e) {
document.write("An unexpected error has occurred.<br>");
document.write("Please contact the administrator.<br>");
document.write(e.message);
} finally {
document.forms[0].submit();
}
return 0; }
</script></head><body>
<form id="frmTest">
Name: <input id="fullName" name="fullName" type="text"><br>
Address: <input id="contactNumber" name="contactNumber" type="text"><br>
<input type="button" value="Submit" onclick="doIt();">
</form></body></html>
| 它将会显示以下信息（如果在字段中没有值输入的话）： 以下为引用的内容：
An unexpected error has occurred.
Please contact the administrator.
First name is missing. | 除此之外，你还可以用运算符instanceof来确定异常的类型，从而做出反应。列表F中的代码会检查异常对象的类型并相应地显示有关数据。 列表F 以下为引用的内容：
<html>
<head>
<title>JS Test</title>
<script type="text/javascript">
function MissingValueException (errMsg) {
this.message = errMsg;
this.name="MissingValueException";
}
function doIt() {
try {
if (document.forms[0].fullName.value == '') {
noNameException = new MissingValueException("First name is missing.");
throw noNameException;
}
} catch(e) {
if (e instanceofMissingValueException) {
document.write(e.message + "<br>");
document.write("Please contact the administrator.<br><br>");
} else {
document.write("An unexpected error has occurred.<br>");
document.write("Please contact the administrator.<br>");
document.write(e.message);
} } finally {
document.forms[0].submit();
} return 0; }
</script></head><body>
<form id="frmTest">
Name: <input id="fullName" name="fullName" type="text"><br>
Address: <input id="contactNumber" name="contactNumber" type="text"><br>
<input type="button" value="Submit" onclick="doIt();">
</form></body></html> |
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| 出处：本站原创 作者：佚名 |
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