You need to test a string to see if it is a valid numeric value.
The isNumeric() function is used to directly test a variable to see if it is numeric.
<cfset testVar = "foo">
A Boolean response (True or False) is returned.
The val() function on the other hand, will go beyond an all or nothing check. It will attempt to parse out a number from the beginning of a string, and return this number if it exists:
<cfset testVar = "100foo"> <cfoutput>#val(testVar)#</cfoutput> 100
If the beginning of the string contains a number, that number is returned. If not, a 0 is returned.
This question was written by Jeremy Petersen
It was last updated on January 12, 2006.