Perl CGI-为特定性选择无线电值
[英]Perl CGI - Picking Radio Values for Specificity
问题描述
I've got a little Perl CGI quiz that I am working on, but I'm completely stuck on it. 
我正在做一些Perl CGI测验，但是我完全坚持了下来。 My HTML code is as follows: 我的HTML代码如下：
<p class="question"><br>1. The answer is Number 1 </p> <ul class="answers"> <input type="radio" name="q1" value="a" id="q1a"><label for="q1a">1912</label><br/> <input type="radio" name="q1" value="b" id="q1b"><label for="q1b">1922</label><br/> <input type="radio" name="q1" value="c" id="q1c"><label for="q1c">1925</label><br/> <input type="radio" name="q1" value="d" id="q1d"><label for="q1d">Summer of '69</label><br/> </ul>
The CGI program is picking the name from the radio button for its parameter value. CGI程序正在从单选按钮中选择名称作为其参数值。 My Perl code is as follows: 我的Perl代码如下：
if ( param("q1") eq undef ) {
$an1 = 0;
$winner = 0;
print <<"BIG";
<h1>You didn't enter the right answer</h1>
BIG
}
else {
print <<"BIG";
<h1>You entered the right answer</h1>
BIG
}
At this point, it will say I entered the right answer if I check any of the radio boxes. 此时，如果我选中任何一个单选框，它将表示我输入了正确的答案。
Is there some way I can specify which value it plucks from radio, like a or b or c or d for the parameter, or am I doing it wrong altogether? 有什么方法可以指定从无线电中提取的值，例如参数的a或b或c或d ，还是我做错了？
3 个解决方案
解决方案1
2 2016-06-11 07:32:55
Please, refer to CGI documentation for details on how to process radio group. 请有关详细信息，请参阅CGI文档 。 To give you an example: 举个例子：
my $cgi = CGI->new;
my $value = $cgi->param('q1');
if ($value eq 'a') { #correct answer
}
else { # incorrect answer
}
Also, eq is a string comparison operator, don't use it to test for undef . 同样， eq是一个字符串比较运算符，不要用它来测试undef 。 Perl has a defined function for this. Perl为此具有defined功能。
解决方案2
1 2016-06-11 09:04:51
You must always use strict and use warnings 'all' at the top of every Perl program. 您必须始终在每个 Perl程序的顶部始终 use strict use warnings 'all'并use warnings 'all' 。 With those in place you would have seen the message Use of uninitialized value in string eq 有了这些，您将看到消息Use of uninitialized value in string eq
You can't compare a value to undef using the string comparator eq . 您不能使用字符串比较器eq将值与undef进行比较。 In your case, param("q1") will be a , b , c or d , or perhaps undef if none of the radio buttons are selected. 在您的情况下， param("q1")将为a ， b ， c或d ，或者如果未选择任何单选按钮，则可能为undef 。 (You would generally make one of the radio buttons selected by default to avoid this, using checked="checked" .) （为避免这种情况，您通常会选择默认选中其中一个单选按钮，方法是使用checked="checked" 。）
Here's a basic CGI program that works fine. 这是一个运行良好的基本CGI程序。
use strict;
use warnings 'all';
use CGI::Minimal;
use File::Spec::Functions 'abs2rel';
my $self = abs2rel($0, $ENV{DOCUMENT_ROOT});
my $cgi = CGI::Minimal->new;
my $q1 = $cgi->param('q1') // 'none';
my $message =
($q1 eq 'a') ? "<h3>You entered the right answer</h3>" :
($q1 ne 'none') ? "<h3>You didn't enter the right answer</h3>" :
'';
print <<END;
Content-Type: text/html
<html>
<head>
<title>Test Form</title>
</head>
<body>
<form action="$self">
<p class="question"><br/>
1. The answer is Number 1
</p>
<ul class="answers">
<input type="radio" name="q1" value="none" id="q1a" checked="checked" />
<label for="q1a"><i>Please choose an answer</i></label>
<br/>
<input type="radio" name="q1" value="a" id="q1a" />
<label for="q1a">1912</label>
<br/>
<input type="radio" name="q1" value="b" id="q1b" />
<label for="q1b">1922</label>
<br/>
<input type="radio" name="q1" value="c" id="q1c" />
<label for="q1c">1925</label>
<br/>
<input type="radio" name="q1" value="d" id="q1d" />
<label for="q1d">Summer of '69</label>
<br/>
</ul>
<input type="submit">
</form>
$message
</body>
</html>
END
解决方案3
1 2016-06-11 12:35:51
you should try this 你应该试试这个
$radio_value = $cgi->param('q1')
also after closing html tag with BIG it seems that it is not ending because its steel red!you write that lines with print! 在用BIG关闭html标记后，似乎也没有结束，因为它的钢红色！
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