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Java TOPIC 23 – ENHANCED FOR LOOP
LESSON NOTE
ITERABLE
INTERFACE Data structures in the Java Collections implement the Collection
interface and the Collection interface implements the Iterable
interface. The iterable interface is a special interface
that allows you to use a special for loop that is often called the enhanced
for loop. The enhanced for loop simply allows for a simpler way to go through a
collection of elements. Regular arrays also implement Iterable
allowing us to use the enhanced for loop to go through each array element. Note: We can also use the enhanced for loop on regular arrays.
The example below shows the enhanced for loop in action. The temporary variable x refers to each
element in arr one after the other. So in the first pass inside the loop, x
refers to arr[0]. In the next
pass, it refers to arr[1]. And then, arr[2]. And so on till it has covered every element
in the array.
MODIFYING THE DATA
STRUCTURE If you
attempt to remove items from a data structure while inside an enhanced for
loop, it will cause a concurrent error.
You should use a regular for loop for this.
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