What defines a recursive function in programming?

A recursive function in programming is defined by the property that it calls itself during its execution. This characteristic allows the function to solve problems by breaking them down into smaller, more manageable instances of the same problem.

For example, consider the calculation of factorials, where the factorial of a number ( n ) can be defined in terms of the factorial of ( n-1 ). The base case typically ensures that recursion terminates successfully at some point, which is essential for avoiding infinite recursion.

This self-referential nature of the function is what distinguishes it from other types of functions that may call different previously defined functions but do not invoke themselves. Additionally, the process of self-calling can facilitate elegant solutions for problems that have repetitive structures, such as tree traversals or searching algorithms, where similar operations are needed at different levels of recursion.