Use a for-loop or a for-each loop? [closed]

Question

Should we prefer the for-each loop instead of the traditional for-loops? Is the while-loop advantageous?

List<String> names = Arrays.asList("John", "Jeff", "Mary", "Elise");

//for-each loop
for(String name: names){
    log(name);
}

//traditional for-loop
for(int index=0; index < 10; ++index){
    log(names.get(index));
}

//Iterator while
Iterator<String> iter1 = names.iterator();
while (iter1.hasNext()) {
    log(iter1.next());
}

//Iterator for loop
for(Iterator<String> iter2 = names.iterator(); iter2.hasNext();){
    log(iter2.next());
}

What is the best flavor to use?

Answer 1

Are are same. But some case one is more favourable then others

Case 1:

//for-each loop
for(String name: names){
    log(name);
}

Favourable :

• When you want to iterate over collection
• no adding or deletion over array.
• No need of index of item you iterate

Case 2:

//traditional for-loop
for(int index=0; index < 10; ++index){
    log(names.get(index));
}

Favourable :

• When you want to iterate over collection
• you need to work on index of item you iterate. So for that you always have value of index you currently on.

Case 3:

Iterator<String> iter1 = names.iterator();
while (iter1.hasNext()) {
    log(iter1.next());
}

and

//Iterator for loop
for(Iterator<String> iter2 = names.iterator(); iter2.hasNext();){
    log(iter2.next());
}

Favourable :

• When you want to iterate over collection
• Addition or deletion take ||ly while iterating.