In this chapter, we discuss how you can use PHP's string functions to format and manipulate text. We also discuss using string functions or regular expression functions to search (and replace) words, phrases, or other patterns within a string.
These functions are useful in many contexts. You often may want to clean up or reformat user input that is going to be stored in a database. Search functions are great when building search engine applications (among other things).
Key topics covered in this chapter include
Joining and splitting strings
Matching and replacing substrings with string functions
Using regular expressions