RECURSIONS.

by: mary trishia v. tabigue

An essential ingredient of recursion is there must be a "termination condition"; i.e. the call to oneself must be conditional to some test or predicate condition which will cease the recursive calling. A recursive program must cease the recursion o n some condition or be in a circular state, i.e. an endless loop which will "crash" the system.

In a computer implementation of a recursive algorithm, a function will conditionally call itself. When any function call is performed, a new complete copy of the function's "information" (parameters, return addresses, etc.. ) is placed into general dat a and/or stack memory. When a function returns or exits, this information is returned to the free memory pool and the function ceases to actively exist. In recursive algorithms, many levels of function calls can be initiated resulting in many copies of th e function being currently active and copies of the different functions information residing in the memory spaces. Thus recursion provides no savings in storage nor will it be faster than a good non-recursive implementation. However, recursive code will o ften be more compact, easier to design, develop, implement, integrate, test, and debug.