Iteration is the process of repeating a set of instructions until a condition is met. It is fundamental to programming and appears in loops, recursion, data processing, and algorithm design. Iteration allows programs to process collections, perform repeated calculations, or explore state changes over time. Many languages offer constructs such as for, while, and foreach to implement iteration.
Why it matters
Iteration enables efficient, dynamic computation on arrays, lists, and other data structures. It is essential for tasks like traversing data models, building transformations, or automating repetitive processes. Incorrect iteration logic can lead to infinite loops, performance issues, or incorrect results.
Examples
Looping through a list of users or incrementing a counter until it reaches a limit. Lessons like What Is a Loop? introduce core iteration ideas.