A subroutine can be coded so that it may call itself recursively in order to perform its task. If there are unsolved problems, the task is recursively carried out to find solutions.
Recursion is used in a variety of disciplines ranging from linguistics to logic. The most common application of recursion is in mathematics and computer science, where a function being defined is applied within its own definition.
The process in which a function calls itself directly or indirectly is called recursion and the corresponding function is called a recursive function. A recursive algorithm takes one step toward solution and then recursively call itself to further move. The algorithm stops once we reach the solution.
In general, code written recursively is shorter and a bit more elegant, once you know how to read it. There is a technique that language implementers can use called tail call optimization which can eliminate some classes of stack overflow.
Recursion involves breaking down a problem into smaller pieces to the point that it cannot be further broken down. You solve the small pieces and put them together to solve the overall problem. Lets understand how recursion really works with the help of an example.
In computer science, recursion is a method of solving a computational problem where the solution depends on solutions to smaller instances of the same problem. [1][2] Recursion solves such recursive problems by using functions that call themselves from within their own code.
To demonstrate the process, let’s take a simple problem. Assume we need to sum up the digits of any given number. For example, the sum of 123 is 6, for 57190 is 22, and so on. So, I need to write a code that solves this problem for me using recursion.