Technology Fundamentals
Recursion
Definition
Recursion in computer science is a method of solving a problem where the solution depends on solutions to smaller instances of the same problem. This is achieved by having a function call itself.
Why It Matters
Recursion provides an elegant way to solve problems that can be broken down into smaller, self-similar sub-problems, such as navigating a tree data structure or calculating a factorial.
Contextual Example
To calculate the factorial of 5 (5!), a recursive function would calculate `5 * factorial(4)`, which in turn calculates `4 * factorial(3)`, and so on, until it reaches the base case of `factorial(1)`, which is 1.
Common Misunderstandings
- A recursive function must have a "base case"—a condition that stops the recursion—otherwise it will lead to an infinite loop and a "stack overflow" error.
- Any problem that can be solved with recursion can also be solved with iteration (loops), but recursion often results in simpler, more readable code for certain types of problems.