IsDefined()

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Evaluates a string value to determine whether the variable named in it exists.

For better performance and security, it's recommended to use StructKeyExists() instead

Status:

deprecated

IsDefined( value=string );

Returns: Boolean

Argument Description
value
string, required 		edit

String, enclosed in quotation marks. Name of variable to test for.

Alias: variable

Examples

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//using isDefined with condition statement
if(isDefined("form.reset")){
	//Code to be Executed
}
str={};
str.value="test";
writeDump(isDefined("str.value"));//true

Related System Properties / Environment Variables

  • LUCEE_ISDEFINED_LIMIT - Alias for lucee.security.limitEvaluation, limits variable evaluation in isDefined
    Type: boolean
  • LUCEE_SECURITY_ISDEFINED - Alias for lucee.security.limitEvaluation, limits variable evaluation in isDefined and related functions
    Type: boolean
  • LUCEE_SECURITY_LIMITEVALUATION - Disable evaluating expressions when accessing scopes, Lucee 7 defaults to enabling this setting for security reasons. A boolean value. If enabled, limits variable evaluation in functions/tags. If enabled, you cannot use expressions within [ ] like this: susi[getVariableName()]. This affects the following functions: IsDefined, structGet, structSort (when using pathToSubElement), empty and the following tags: savecontent attribute `variable`
    Type: boolean, Default: false (Lucee 6), true (Lucee 7)

See also