That makes the variable exist only for the duration of that method call.
For instance, you have a CFC which is persisted in the application
scope.
<cfset application.my_cfc = CreateObject('component','CFC.foo')>
It has a method called helloWorld() which queries their name out of the
database a returns it.
<cfquery name="qry_your_name">
Select etc.
</cfquery>
<cfreturn qry_your_name.full_name>
Now, let's say two different people in the same app call that method at
the same time. Right now, qry_your_name will exist in variables, which
is global to the entire CFC.
Here we just created a race condition. User one's query runs, and then
user two's query overwrites. Then the cfreturn hands back the same data
to both users.
The solution:
<cfset var qry_your_name = "">
<cfquery name="qry_your_name">
Select etc.
</cfquery>
<cfreturn qry_your_name.full_name>
Now EACH call to that method has its own qry_your_name variable which
can not be overwritten by concurrent usage of the CFC
Print this out and place it on your cube wall. I did. :)
http://www.coldfusionjedi.com/downloads/cfcscopes.pdf
~Brad
-----Original Message-----
From: Chad Gray [mailto:[EMAIL PROTECTED]
Sent: Monday, July 30, 2007 8:46 AM
To: CF-Talk
Subject: CFC defining vars
I have noticed in a lot of people's code for CFCs they set all of the
variables being used in the CFC like this:
<cfset var foo = "">
Why? Is this just good programming practice?
Also what scope are these variables in? variables.foo?
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