java - Is there a performance difference between a for loop and a for-each loop? -

what, if any, performance difference between following 2 loops?

for (object o: objectarraylist) {     o.dosomething(); } 

and

for (int i=0; i<objectarraylist.size(); i++) {     objectarraylist.get(i).dosomething(); } 

from item 46 in effective java joshua bloch :

the for-each loop, introduced in release 1.5, gets rid of clutter , opportunity error hiding iterator or index variable completely. resulting idiom applies equally collections , arrays:

// preferred idiom iterating on collections , arrays (element e : elements) {     dosomething(e); } 

when see colon (:), read “in.” thus, loop above reads “for each element e in elements.” note there no performance penalty using for-each loop, arrays. in fact, may offer slight performance advantage on ordinary loop in circumstances, computes limit of array index once. while can hand (item 45), programmers don’t so.