Java foreach loop for Integer i list

Question

When I use JDK5 like below  ArrayList lt Integer gt  list   new ArrayList lt Integer gt            for  Integer i   list              cannot check if already reached last item         on the other hand if I just use an Iterator  ArrayList lt Integer gt  list   new ArrayList lt Integer gt       for  Iterator i   list iterator    i hasNext                    i can check whether this is last item           if i hasNextItem                          How can I check if I ve already reached last item with   for  Integer i   list

User · Answer

Another way  you can use a pass-through object to capture the last value and then do something with it   List lt Integer gt  list   new ArrayList lt Integer gt     Integer lastValue   null  for  Integer i   list           do stuff     lastValue   i       do stuff with last value

User · Answer

One way to do that is to use a counter   ArrayList lt Integer gt  list   new ArrayList lt Integer gt         int size   list size    for  Integer i   list                 if  --size    0               Last item                        Edit  Anyway  as Tom Hawtin said  it is sometimes better to use the  old  syntax when you need to get the current index information  by using a for loop or the iterator  as everything you win when using the Java5 syntax will be lost in the loop itself     for  int i   0  i  lt  list size    i                   if  i     list size   - 1                Last item              or   for  Iterator it   list iterator    it hasNext                     if   it hasNext                 Last item

User · Answer

The API does not support that directly  You can use the for int i    loop and count the elements or use subLists 0  size - 1  and handle the last element explicitly     if x isEmpty    return    int last   x size   - 1    for Integer i   x subList 0  last   out println i     out println  last     x get last      This is only useful if it does not introduce redundancy  It performs better than the counting version  after the subList overhead is amortized    Just in case you cared after the boxing anyway

User · Answer

Sometimes it s just better to use an iterator    Allegedly   85   of the requests for an index in the posh for loop is for implementing a String join method  which you can easily do without

[java] Java foreach loop: for (Integer i : list) { ... }

Examples related to java

Examples related to iterator

Examples related to foreach