August 2003
Intermediate to advanced
1140 pages
68h 45m
English
IsDefined
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>