Chapter 21. Sorting, Searching, and Random Numbers
Topics in This Chapter
Sorting and searching are two fundamental concepts of computer science. They are closely tied to almost every application: databases, compilers, even the World Wide Web. The more information you have online, the more important it becomes to know exactly where that information is.
Admittedly, sorting is not as serious a topic in the context of PHP as it is for C++. PHP offers some very powerful sorting functions, even one that allows you to define how to compare two elements. This chapter deals with some classic problems of computer science. You may be interested in learning about the concepts that become useful as you use more generalized languages like C or Ada. But further than that, these concepts will help you understand the internal workings of databases, Web servers, even PHP itself. You will be more capable of dealing with the inevitable problem unsolved by any built-in PHP function.
This chapter also discusses random numbers, which are useful for putting data out of order. The practical application of this usually takes the form of unique identifiers, for files or sessions.
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