IsInstanceOf()

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Determines whether an object is an instance of a Lucee interface or component, or of a Java class.

IsInstanceOf( obj=any, type=string );

Returns: Boolean

Argument Description
obj
any, required 		edit

The CFC instance or Java object that you are testing

Alias: value
type
string, required 		edit

The name of the interface, component, or Java class of which the object might be an instance.

Usage Notes

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IsInstanceOf accepts three type-string forms for components.

For each component in the inheritance chain, the runtime checks the type string against three things — any match is enough:

  1. The bare class name — the last segment of the loading path, e.g. Child for a CFC at mypackage/SubFolder/Child.cfc.
  2. The loading-context-relative path that was passed to new, e.g. SubFolder.Child when instantiated from inside mypackage/.
  3. The fully-qualified path from the web root, which is what getMetaData( c ).name returns, e.g. mypackage.SubFolder.Child.

Matches are case-insensitive. The check walks the extends chain and any interfaces declared via implements on the component or its ancestors.

var c = new mypackage.SubFolder.Child();   // extends ParentBase implements MyInterface
isInstanceOf( c, "Child" );                            // true — bare class name
isInstanceOf( c, "mypackage.SubFolder.Child" );        // true — full path
isInstanceOf( c, getMetaData( c ).name );              // true — same as above
isInstanceOf( c, "ParentBase" );                       // true — extends chain
isInstanceOf( c, "MyInterface" );                      // true — implements (incl. from ancestors)
isInstanceOf( c, "Component" );                        // true — every CFC matches

A path slice that's none of those three forms (e.g. SubFolder.Child when the loading path was different) returns false.

Java class checks accept the FQCN, plus a small shortlist of bare names.

For Java types, pass the fully-qualified Java class or interface name (e.g. java.util.Map, java.lang.String) — Lucee runs the standard instanceof check against the underlying Java object.

A few bare names also resolve, via a hardcoded shortlist in ClassUtil.checkPrimaryTypes: the Java primitives (boolean, int, long, float, double, byte, char, short), plus Object, String, Integer, Character, plus the CFML synonyms Numeric (= Double) and Null (= Object). Other bare Java names (Map, CharSequence, Comparable, etc.) do not resolve — use the FQCN.

Examples

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writeDump(isInstanceOf({},"java.util.Map")); // true
writeDump(isInstanceOf("Lucee","java.util.Map")); // false
writeDump(isInstanceOf("Lucee","java.lang.String")); // true

See also