React hooks. DOM trees. Nested comments. You've been using recursion this whole time

• Recursion is when a function calls itself to solve a smaller version of a problem.

• Every recursive function needs:

A base case → stops the recursion

A recursive case → continues the recursion

• A countdown function is a simple example:

countdown(5) → 5, 4, 3, 2, 1

• Recursion is commonly used in:

Nested comments

File/folder navigation

React component trees

DOM traversal

Search algorithms

• Popular recursion examples:

Factorial

Fibonacci sequence

Binary search

Tree traversal

• Recursion works best for problems with nested or repeating structures.