Loops and references

loops.php

<?php

// Normal foreach loop
foreach($foo as $bar)
{
...
}

// Foreach with reference
foreach($foo as &$bar)
{
    //Modifying $bar affects the object/array you are looping over
}

// Foreach with key/value
foreach($foo as $bar => $baz)
{
    // Handy for when you need a numeric or associative index
}

So...you can do most anything with just foreach loops.