The function java-object-array-element-type
returns the element type (as a keyword as listed in Types and conversion between Lisp and Java) if object is an array with non-primitive element type. If object is some other type of Java object, java-object-array-element-type
returns nil
. Otherwise it signals an error.
java-object-array-element-type
to test whether a Java object is an array of non-primitive element type.If you want to check whether object is any array (primitive or not), use java-array-element-type instead. Sometimes java-primitive-array-element-type may be more convenient.
LispWorks User Guide and Reference Manual - 20 Sep 2017