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Join Date: Oct 2004
Location: San Francisco, CA
Posts: 337
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Solved Threads: 1
Posting Whiz
I am in the process of learning JSP and my question is how do I check to see if a variable exists? The equivalent of this in php would be
[php]if (isset($_POST['someVar']))[/php] or
[php]if (isset($_GET['someVar']))[/php]
any and all help would be appreciated!
[php]if (isset($_POST['someVar']))[/php] or
[php]if (isset($_GET['someVar']))[/php]
any and all help would be appreciated!
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Join Date: Dec 2004
Location: Lincoln Park, Michigan
Posts: 1,744
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I'm pretty sure you can use defined in javascript. You can try:
I'm not sure, but I think that's accurate.
if (defined(somevariable)) {
alert(somevariable);
}I'm not sure, but I think that's accurate.
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Join Date: Oct 2004
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Posting Whiz
that wont work because i need it to be serverside, otherwise i might as well do it in html/javascript instead of jsp
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Join Date: Dec 2004
Location: Lincoln Park, Michigan
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You are talking about a regular variable right? Or are you talking about an evirionment variable?
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Join Date: Nov 2004
Location: Netherlands
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You mean a request or session attribute?
It's easy.
Actually if it's just to prevent errors when outputting something you don't need to check, JSTL is smart enough to ignore anything that's not there so
would just output nothing at all if someVar weren't there.
It's easy.
<c:if test="${not empty someVar}">
<%-- do what you need to do when the attribute is there --%>
</c:if>Actually if it's just to prevent errors when outputting something you don't need to check, JSTL is smart enough to ignore anything that's not there so
<c:out value="${someVar}"/> 42 Private messages asking for help will be ignored
In the frozen land of Nador they were forced to eat Steve's iMinstrels, and there was much rejoicing.
In the frozen land of Nador they were forced to eat Steve's iMinstrels, and there was much rejoicing.
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Join Date: Oct 2004
Location: San Francisco, CA
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Posting Whiz
i mean like a get (from url) or posted (client connection) variable
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Join Date: Dec 2004
Location: Lincoln Park, Michigan
Posts: 1,744
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Hmn, will this help any: http://www.experts-exchange.com/Web/...21299007.html?
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