Default CFParam Expressions Are Always Executed In ColdFusion

<cfscript>


	// I return a default value for use in an optional parameter.
	numeric function getDefaultValue() {

		return( ++defaultValue );

	}


	// ------------------------------------------------------ //
	// ------------------------------------------------------ //


	// Since the defaultValue is pre-incremented above, we will be
	// able to see how many times the getDefaultValue() method is
	// actually invoked at runtime.
	defaultValue = 0;

	// Setup THREE out of FIVE optional parameters.
	url.a = "exists-already";
	url.b = "exists-already";
	url.c = "exists-already";

	// Now, param five values. Since we have the three above, only
	// two of the five below should receive the default value.
	param name = "url.a" type = "any" default = getDefaultValue();
	param name = "url.b" type = "any" default = getDefaultValue();
	param name = "url.c" type = "any" default = getDefaultValue();
	param name = "url.d" type = "any" default = getDefaultValue();
	param name = "url.e" type = "any" default = getDefaultValue();

	// At this point, "defaultValue" will report the number of
	// times the getDefaultValue() expression was executed.
	writeOutput( "Script Result: " & defaultValue );

	// Output the URL values at this point, so we can see which
	// values were defined.
	writeOutput( "<br />" );
	writeOutput( "Url: #a#, #b#, #c#, #d#, #e#" );


</cfscript>