Recursion

A recursive function is a function which calls itself.

Here’s how it goes: beginning recursion -> recursive loop of repeating a task -> until we hit our base case.

a function being defined is applied within its own definition. While this apparently defines an infinite number of instances (function values), it is often done in such a way that no loop or infinite chain of references can occur.

Recursion is the process a procedure goes through when one of the steps of the procedure involves invoking the procedure itself.

Notes

• like while loops but much cleaner
• self-referential definitions
• Recursion vs. Iteration: Iteration explicitly uses repetition structures to achieve results. Recursion on the other hand repeats through function calls
• a base case is used to stop recursion

There are 4 distinct pieces of a recursive function:

1. Repeated task: this is the function task you want to run on each function invocation
2. Base case: this is how we stop recursion! when the base case condition is met, recursion stops. it’s very important you stop a recursive function, otherwise it’ll keep recurring infinitely
3. Recursion: this is where we run the function again
4. Beginning recursion: this is where we kick things off!

Links

• Understanding recursion (Javascript example)
• Codecademy: Recursion in JavaScript
• https://en.wikipedia.org/wiki/Recursion
• https://www.cs.umd.edu/class/fall2002/cmsc214/Tutorial/recursion.html
• https://www.youtube.com/watch?v=t4MSwiqfLaY