Nested loops are loops inside other loops. They are used when a task requires repeating one action inside another repeated action.
For example, when working with tables, grids, patterns, or multi-dimensional data, nested loops help process every row and every column.
Understanding nested loops is important for solving more complex problems and building real-world features like reports, charts, and game boards.
When to Use Nested Loops
- When working with tables or matrices
- When generating patterns
- When comparing items from two lists
- When building grid-based layouts
- When processing multi-level data
Nested loops allow programs to handle complex repetition efficiently.
In this example, the outer loop controls the rows and the inner loop controls the columns.
For each value of i, the inner loop runs completely. This shows how nested loops repeat tasks inside tasks.
This example uses nested loops to print a simple pattern. The outer loop controls the number of lines, and the inner loop controls how many stars appear in each line.
Pattern printing is a common exercise for understanding nested loops.
This example shows how nested loops can be used to combine data from two lists.
By mastering nested loops, students gain the ability to handle complex data processing and move closer to building professional-level applications.