Recursion

The act of a function calling itself, recursion is used to solve problems that contain smaller sub-problems. A recursive function can receive two inputs: a base case (ends recursion) or a recursive case (resumes recursion).

Examples

Recursive function calls itself until condition met

The following Python code defines a function that takes a number, prints it, and then calls itself again with the number's value -1. It keeps going until the number is equal to 0, in which case it stops.

def recurse(x):
   if x > 0:
       print(x)
       recurse(x - 1)

recurse(10)

The output will look like this:

10
9
8
7
6
5
4
3
2
1

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General knowledge