Name

IsDefined

Synopsis

IsDefined('variable_name')

Determines if the specified variable exists. Returns True if the specified variable exists or False if it doesn’t. Note that IsDefined( ) replaces the deprecated ParameterExists( ) function. Examples: 

<CFSET MyVar="Variable">
<CFSET Form.MyFormVar="Form Variable">

<CFOUTPUT>
<CFIF IsDefined('MyVar')>
  Variable MyVar exists:<BR> MyVar = #MyVar#
<CFELSE>
  No variable called MyVar exists.
</CFIF>
<P><CFIF IsDefined('MyFormVar')>
  Variable MyFormVar exists:<BR> MyFormVar = #MyFormVar#
<CFELSE>
  No variable called MyFormVar exists.
</CFIF>
<P><CFIF IsDefined('Queryname.field')>
  Variable Queryname.Field exists:<BR> QueryName.Field = #Queryname.Field#
<CFELSE>
  No variable called Queryname.Field exists.
</CFIF>
</CFOUTPUT>

Get Programming ColdFusion now with the O’Reilly learning platform.

O’Reilly members experience books, live events, courses curated by job role, and more from O’Reilly and nearly 200 top publishers.

Start your free trial