Category:Recursion: Difference between revisions

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More than one end condition is allowed. More than one recursion condition is allowed.

Many recursion problems can be solved with an iterative method, or using a [[loop]] of some sort (usually recursion and iteration are contrasted in programming, even though recursion is a specific type of iteration). In some languages, the factorial example is best done with a loop because of function call overhead. Some other languages, like [[Scheme]], are designed to favor recursion over explicit looping, using [[tail recursion]] optimization to convert recursive calls into loop structures. If loop structures are not available in your language (or not allowed by the rules of your task), recursion is a good way to go.

Many recursion problems can be solved with an iterative method, or using a [[loop]] of some sort (usually recursion and iteration are contrasted in programming, even though recursion is a specific type of iteration). In some languages, the factorial example is best done with a loop because of function call overhead. Some other languages, like [[Scheme]], are designed to favor recursion over explicit looping, using tail recursion optimization to convert recursive calls into loop structures. If loop structures are not available in your language (or not allowed by the rules of your task), recursion is a good way to go.

'''Tail recursion''' is a specific type of recursion where the recursion call is the last call in the function. Because tail recursive functions can easily and automatically be transformed into a normal [[:Category:Iteration|iterative]] functions, tail recursion is used in languages like Scheme or [[OCaml]] to optimize function calls, while still keeping the function definitions small and easy to read. The actual optimization transforms recursive calls into simple branches (or jumps) with logic to change the arguments for the next run through the function.