CF9: Datatype of sum of two integer

I had an interesting observation about datatype conversion in CF9 when dealing with an error in ORM. I was getting an error that said can't use double for an integer field type (something like that). Now, I know that ColdFusion is datatype "independent". So, all simple variables are of datatype "String". Given that, when we do:

<cfset myVar = 1 />
<cfdump var="#getMetaData(myVar).toString()#" />

The result is "class java.lang.string". Now, if we perform a sum:

<cfset myVar = 1 + 1 />
<cfdump var="#getMetaData(myVar).toString()#" />

The result is "class java.lang.Double". I expected it to be integer. I was assuming that on the Java side they will get converted to integer. So, next I tried:

	<cfset myVar = javaCast("int",1) + javaCast("int",1) />

And the result was still "class java.lang.Double".

So, is sum of two integer result in a "Double"? I will let people who are more intelligent than me answer and explain that to me.

But, in the mean time it causes issue when dealing with ORM. I was doing something like this:

	var hql = "SELECT IsNull(MAX(sortOrder),0) FROM " & arguments.entity.getEntityName() ;
var newSortOrder = ORMExecuteQuery(hql,true) + 1;
arguments.entity.setSortOrder(newSortOrder);

This was throwing an error because the datatype of sortOrder field is integer and the type of newSortOrder was "Double". The error can be fixed by using javaCast("int",newSortOrder), but I just changed my select to "IsNull(MAX(sortOrder),0)+1" and it returned me a integer.

Anyone care to explain me why sum of two integer results in a Double in ColdFusion?

Comments

Ben Nadel: Regardless of why ColdFusion switches data types (it is a dynamic language), what I find scary is that the ORM is NOT doing JavaCast() or CFQueryParam/cfsqltype behind the scenes?? That feels very much like a bug.; January 23, 2010, 6:30 PM; Reply