What is diffrence between diffrent for loop in Java? [on hold]

What is diffrence between diffrent for loop in Java? [on hold]

Java have different for loops to walk through from list like:
public void myMethod(List list){
for(int i=0;i<=list.size();i++){
//Here write some code
}
}
Or we can write something like this
public void myMethod(List list){
for(String obj : list){
//Here write some code
}
}
These are some samples of code. Or We can say List Iterator
public void myMethod(List list){
Iterator<String> iterator = list.iterator();
while (iterator.hasNext()) {
System.out.println(iterator.next());
}
}
Which one is better and prevent from NullPointerException without any more
code writing?