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IsInstanceOf
DescriptionDetermines
whether an object is an instance of a ColdFusion interface or component,
or of a Java class.
ReturnsReturns
true if any of the following is true:
The object specified
by the first parameter is an instance of the interface or component
specified by the second parameter.
The Java object specified by the first parameter was created
by using the cfobject tag or CreateObject method
and is an instance of the Java class specified by the second parameter.
The object specified by the first parameter is an instance
of a component that extends the component specified in the second
parameter.
The object specified by the first parameter is an instance
of a component that extends a component that implements the interface
specified in the second parameter.
The Java object specified by the first parameter was created
by using the cfobject tag or CreateObject method
and is an instance of a Java class that extends the class specified
by the second parameter.
Returns false otherwise.
Note: The isInstanceOf function returns false if
the CFC specified by the object parameter does
not define any functions.
Function syntaxIsInstanceOf(object, typeName)
HistoryColdFusion
8: Added this function.
Parameters
Parameter
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Description
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object
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The CFC instance or Java object that you
are testing
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typeName
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The name of the interface, component, or
Java class of which the object might be an instance
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UsageFor Java
objects, the comparison is valid only if you created the object
specified in the first parameter by using a cfobject tag
or CreateObject method.
Example<!--- to use this example, create an I1.cfc interface, as follows: --->
<cfinterface>
<cffunction name = "method1">
</cffunction>
</cfinterface>
<!--- Create a C1.cfc component that implements the I1.cfc interface, as
follows: --->
<cfcomponent implements=I1>
<cffunction name = "method1">
<cfoutput>C1.method1 called</cfoutput>
</cffunction>
</cfcomponent>
<!--- Create a test.cfm file as follows and display the page. --->
<!--- Create an instance of the C1 CFC, which implements the I1 interface.
--->
<cfset c1obj = CreateObject("Component", "C1")>
<!--- Create a Java object --->
<cfset javaObj = createobject("java", "java.lang.System")>
<cfoutput>
IsInstanceOf(c1obj,"C1") = #IsInstanceOf(c1obj,"C1")#
(Expected = YES)<br><br>
IsInstanceOf(c1obj,"I1") = #IsInstanceOf(c1obj,"I1")#
(Expected = YES)<br><br>
IsInstanceOf(c1obj,"C2") = #IsInstanceOf(c1obj,"C2")#
(Expected = NO)<br><br>
IsInstanceOf(javaObj,"java.lang.System") =
#IsInstanceOf(javaObj,"java.lang.System")# (Expected = YES)<br><br>
IsInstanceOf(javaObj,"java.lang.String") =
#IsInstanceOf(javaObj,"java.lang.String")# (Expected = NO)<br><br>
</cfoutput>
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