# How to Optimize Loops

* Sometimes you'll encounter loops, or recursive functions, that take a long time to execute and are bottlenecks in your system
* First, search for a way of removing the loop entirely before looking to optimise
* Recursion, can lead to code being more complex and harder to understand, if you value development performance over system performance then consider replacing these
  * use of functinoal ways, ie streams, lambdas might be better
* Optimising loops
  * Move as much stuff out of the loop, so actions are not repeated
    * Example
      * Remove floating point operations.
      * Don't allocate new memory blocks unnecessarily.
      * Fold constants together.
      * Move I/O into a buffer.
      * Try not to divide.
      * Try not to do expensive typecasts.
      * Move a pointer rather than recomputing indices.
      * String creation
  * If you are looping of data in memory, but this came from a database, instead of doing it in code, let the database do it for you (it is optimised to handle this)
  * These can be language specific