The following functions let you use arrays in various ways throughout your program.
When you are done working with array values, sometimes it is nice to get rid of them altogether. You might need to use them again later in the program, and want to reuse the keys without worrying about overwriting data. PHP offers the unset() function to get rid of old array values (or, for that matter, old arrays). The function unset() works by only unsetting exactly the parameter you pass to it. Unsetting an array is useful for memory management.
If you want to create an array with five values, you could write something like the following, which ends up looking like Figure 10.5: