Switch Statements Not Case Sensitive
Posted July 31, 2006 at 8:01 AM
I know that ColdFusion is case insensitive by nature. It had never occurred to me though that conditional statements were also case insensitive. I am such a huge user of ListFind() and Compare(), both of which are case SENSITIVE, that I just started to assume that all conditionals were case sensitive. That's the reason why my custom tags end up looking like:
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- <cfswitch expression="#UCase( THISTAG.ExecutionMode )#">
- <cfcase value="START">
- <!--- ... --->
- </cfcase>
- <cfcase value="END">
- <!--- ... --->
- </cfcase>
- </cfswitch>
I upper case the ExecutionMode variable because I am never sure what value it is going to be. Apparently though, as I just found out, that is entirely unnecessary. Switch statements, as well as all other simple conditional statements, are NOT case sensitive. To experiment a bit, I tried doing this:
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- <!--- Set a value with mixed case. --->
- <cfset strValue = "Cool">
-
- <!--- Check values without case sensitivity. --->
- <cfswitch expression="#strValue#">
-
- <!--- Check with same case. --->
- <cfcase value="Cool">
- It is Cool.
- </cfcase>
-
- <!--- Check with lower case. --->
- <cfcase value="cool">
- It is cool.
- </cfcase>
-
- </cfswitch>
Both cases above are the same word, but with different letter casing. Turns out, the above example throws an error:
Context validation error for tag CFCASE.
The CFSWITCH has a duplicate CFCASE for value "COOL".
ColdFusion is seeing the two "Cool" cases as having the same value. Then, just to double-check that I am not going completely crazy, I tested the case-insensitive check without duplicate values:
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- <!--- Check values without case sensitivity. --->
- <cfswitch expression="#strValue#">
-
- <!--- Check with a different case. --->
- <cfcase value="COOL">
- This is COOL
- </cfcase>
-
- <!--- Check with different value. --->
- <cfcase value="LAME">
- This is LAME
- </cfcase>
-
- </cfswitch>
This one does indeed access the first case statement value of COOL even though the original value was mixed-case.
I am not 100% sure how I feel about this. On one hand, I like that fact that I don't have to worry about cases in conditional statements. On the other hand though, I like the fact that ListFind() and Compare() are case sensitive and that I can leverage that in certain ways. I guess overall, it is going to create less bugs. And, now that I know it, I don't have to waste processing power changing the letter-casing of my switch statements.
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