(1)for each for(bject o :list) { } [java] view plain copy (2)Iterator Iterator iter = list.iterator(); while(iter.hasNext()){ Object o = iter.next(); } (3)loop without size int size = list.size(); for(int i=0;i<size;i++){ Object o= list.get(i); } (4)loop with size for(int i=0;i<list.size();i++){ Object o= list.get(i); }