Nested Loops

Nested Loops in Kotlin

Nested loops let you place one loop inside another. This approach is useful when you need to repeat an action within another repeated action, such as working with grids, tables, or multi-dimensional data.

What Is a Nested Loop?

A nested loop is when you use a loop (such as a for, while, or do-while loop) inside the body of another loop. The inner loop finishes all its cycles for each step of the outer loop.

Why Use Nested Loops?

• Process data in two or more dimensions, like a chessboard or spreadsheet;
• Compare every element in one collection with every element in another;
• Generate combinations or pairs of values.

How Nested Loops Work

The outer loop starts and runs its first cycle. Inside that cycle, the inner loop runs all its cycles. Once the inner loop finishes, the outer loop moves to its next cycle, and the inner loop runs again. This pattern continues until the outer loop finishes all its cycles.

Common Use Cases

• Printing patterns or shapes with text;
• Working with two-dimensional arrays or lists of lists;
• Searching for matching pairs in data.

Nested loops are a powerful tool, but be careful: they can make your code run slower if you use them with large data sets. Always look for the simplest approach that meets your needs.