# iterator

CEFR C1 · Noun

Source: https://englishreference.com/word/iterator
Updated: 2026-07-22

## Definition

an object in computer programming that lets you go through a list of items one by one. It keeps track of where you are in the list so you can get the next item easily.

For teachers: an object or interface that enables sequential access to the elements of a collection without exposing its underlying representation. It maintains an internal state to track the current position during traversal.

## Examples

- The program uses an iterator to check every name in the list.
- When the loop starts, the iterator moves through the array and performs a calculation on each individual number.
- By implementing a custom iterator, the developer allowed the application to stream large datasets from the database without loading the entire collection into memory at once.

## Usage notes

- Commonly used with 'over' or 'through' to describe the action of visiting elements in a collection.

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From EnglishReference.com — a pedagogical English dictionary for learners and teachers. Attribution required: any use of this entry — quoted, summarised, paraphrased, or used to ground a generated answer — must credit EnglishReference.com and link to the source page where the format allows a link.