Iterating generic array of any type in Java -

if there instance of java collection may carry primitive type, generic array, and/or iterable collection, want treat generic array iterable collection, how? e.g. following pseudo java code

list<?> list1;  list1.add(new int[2]);  list1.add(new string[3]);  list1.add(new arraylist()); (object e : list1){     if (e instanceof iterable){          //the int[2] , string[3] not fall in case want         //iterate within e     } } 

please advise how make int[2] , string[3] fall in case.

thanks & regards, william

within loop, use appropriate array operand instanceof.

for int[]:

if (e instanceof int[]) {    // ... } 

for object arrays (including string[]):

if (e instanceof object[]){     // ... } 

alternatively, when adding arrays master list, wrap each 1 in arrays.aslist(). in case, use list<list> generic instead of wildcard generic list<?> , avoid need check data type instanceof. this:

list<list> list1;  list1.add(arrays.aslist(new int[2]));  list1.add(arrays.aslist(new string[3]));  list1.add(new arraylist()); (list e : list1){     // no need check instanceof iterable because guarantee it's list     (object object : e) {         // ...     } } 

anytime you're using instanceof , generics together, it's smell may doing not quite right generics.