How to Access Iteration Count in Java's For-Each Loop?

Is there a way to access an iteration counter within Java's for-each loop?

for(String s : stringArray) {
  doSomethingWith(s);
}

In Java, the for-each loop (enhanced for loop) does not provide a built-in iteration counter. However, there are ways to effectively track the iteration count while still using the for-each style of loop. This article explores a few methods to achieve this, along with examples.

int counter = 0;
for (String s : stringArray) {
    doSomethingWith(s);
    counter++;
}
System.out.println("Current iteration count: " + counter);

Causes

• The for-each loop is designed for simplicity and does not expose the index of the current iteration.

Solutions

• Use a separate counter variable initialized before the loop, that you manually increment within the loop for each iteration.
• You can use Java Streams with the IntStream to achieve a similar result with counting.

Mistake: Using a for-each loop with a simple variable read instead of a proper counter variable.

Solution: Always initialize and manage your counter variable inside the loop to ensure accurate counts.

Mistake: Assuming that the for-each loop gives an index automatically, leading to errors when using it.

Solution: Remember that for-each is meant for convenience over index management; use a standard for loop if index tracking is necessary.