TheAlgorithms/Java · error · NoSuchElementException

No more elements in the bag.

Error message

No more elements in the bag.

What it means

Thrown by Bag's iterator next() when hasNext() is false — i.e., the iterator has been fully consumed and there are no more elements. This is the standard contract violation for java.util.Iterator: calling next() after exhaustion.

Source

Thrown at src/main/java/com/thealgorithms/datastructures/bags/Bag.java:131

         * Checks if there are more elements to iterate over.
         *
         * @return {@code true} if there are more elements; {@code false} otherwise
         */
        @Override
        public boolean hasNext() {
            return currentElement != null;
        }

        /**
         * Returns the next element in the iteration.
         *
         * @return the next element in the bag
         * @throws NoSuchElementException if there are no more elements to return
         */
        @Override
        public E next() {
            if (!hasNext()) {
                throw new NoSuchElementException("No more elements in the bag.");
            }
            E element = currentElement.content;
            currentElement = currentElement.nextElement;
            return element;
        }
    }
}

View on GitHub (pinned to fdfb9a395b)

Solutions

1. Always check hasNext() before next() in explicit iterator loops.
2. Prefer the enhanced for-each loop which handles the check automatically.
3. For empty bags, short-circuit before iterating.

Example fix

// before
Iterator<E> it = bag.iterator();
while (true) { E e = it.next(); /* process */ }
// after
for (E e : bag) { /* process */ }
// or explicitly:
Iterator<E> it = bag.iterator();
while (it.hasNext()) { E e = it.next(); /* process */ }

// Always check hasNext before next
Iterator<E> it = bag.iterator();
while (it.hasNext()) {
    E e = it.next();
    // process e
}

Iterator<E> it = bag.iterator();
try {
    while (true) {
        E e = it.next();
        // process
    }
} catch (NoSuchElementException e) {
    // iteration complete
}

When it happens

Trigger: Calling iterator.next() without guarding with hasNext(); using a raw while(true) loop that doesn't check hasNext(); calling next() on an iterator obtained from an empty bag.

Common situations: Manual iteration loops that forget the hasNext check; for-each loops are safe but explicit iterator.next() calls in while loops are error-prone; reusing an exhausted iterator.

Related errors

• No converter for: {}
• Number of hash functions and bit array size must be greater
• Buffer size must be positive
• Null items are not allowed
• Cannot pop from an empty stack.

AI-assisted analysis of TheAlgorithms/Java@fdfb9a395b (2026-08-13). Data as JSON: /api/errors/4b9553f558a2510a. Report an issue: GitHub.