Sams Teach Yourself PHP in 24 Hours, Third Edition

Associative Arrays

Numerically indexed arrays are useful for storing values in the order they were added or according to a sort pattern. Sometimes, though, you need to access elements in an array by name. An associative array is indexed with strings between the square brackets rather than numbers. Imagine an address book. Which would be easier, indexing the name field as 4 or as name?

Again, you can define an associative array using either array() or the array operator [].

The division between an associative array and a numerically indexed array is not absolute in PHP. They are not separate types as arrays and hashes are in Perl are. Nevertheless, ...