On the SitePoint PHP blog today there's a new post from Craig Buckler looking (quickly) at a handy feature of the Standard PHP Library (SPL) that can help make working with objects and arrays simpler - object iterators.
If you’ve been coding in PHP for a while, you may be familiar with the foreach loop. It provides an easy way to analyze every item in an array. As well as arrays, it’s also possible loop through an object. If your object contains a collection of items, you can use a foreach loop to iterate over each of them. [...] Iterators is a subject which strikes fear into the heart of many developers. They sound complex and are often explained with indecipherable abstract references.
To help combat this impression, he gives a bit more practical example - turning a regular array into an ArrayIterator and looping through the collection as an object instead of just a variable. This helps to keep things contained.