What is the purpose of using final for the loop variable in enhanced for loop?

I understand how the below statement works.

for(final Animal animal : animalList){
//do some function
}

But what is the purpose of using the final keyword here ?

Solution

There are two possible reasons to do this:

It could simply be a way to avoid changing the loop variable accidentally in the loop body. (Or to document the fact that the loop variable is not going to be changed.)
It could be done so that you can refer to the loop variable in an anonymous inner class. For example:
```
for(final Animal animal : animalList){
    executor.submit(new Runnable(){
        public void run() {
            animal.feed();
        }
    });
}
```
It is a compilation error if you leave out the final in this example.

UPDATE it is not a compilation error in Java 8 and later versions. The non-local variable is now only required to be effectively final. In simple terms, that means that the variable is not assigned to (using an assignment operator or a pre/post increment or decrement operator) after the initial declaration / initialization.