April 20, 2006


New to ColdFusion MX7 the isValid() function tests whether a value meets a validation or data type rule and returns True if the value conforms to the rule; False, otherwise.

Function syntax

isValid(type, value)
isValid("range", value, min, max)
isValid("regex" or "regular_expression", value, pattern)


<cfif IsValid("integer", url.value)>
   Valid integer!
   Invalid Integer!

<cfif IsValid("range", url.value, 1, 100)>
   Value is between 1 and 100
   Value is not between 1 and 100

<cfif IsValid("regex", url.value, "[A-Z][a-z]+")>
   Word starts with a capital letter
   Word does not match pattern.

There are a lot of pre-existing functions that can already do a lot of what isValid() offers like:

  • isNumeric()
  • isBoolean()
  • isArray()
  • isQuery()
  • isStruct

But with isValid() you can do those as well as things like:

  • creditcard (mod10 checks for credit cards)
  • email
  • eurodate
  • guid
  • range
  • regex
  • url
  • usdate
  • variablename (a string formatted according to ColdFusion variable naming conventions)

There are also a few US specific test conditions as well like “ssn” and “telephone” etc.

All in all this is an extremely versatile tag to use for validation and will save you oodles of time!

© Michael Sharman 2017