(PECL mongo >=0.9.0)
MongoDB::listCollections — Gets an array of all MongoCollections for this database
$includeSystemCollections = false
  ] )Gets a list of all the collections in the database and returns them as an array of MongoCollection objects.
includeSystemCollectionsInclude system collections.
Returns an array of MongoCollection objects.
| Version | Description | 
|---|---|
| 1.3.0 | Added the includeSystemCollectionsparameter. | 
Example #1 MongoDB::listCollections() example
The following example demonstrates dropping each collection in a database.
<?php
$m = new MongoClient();
$db = $m->selectDB("sample");
$list = $db->listCollections();
foreach ($list as $collection) {
    echo "removing $collection... ";
    $collection->drop();
    echo "gone\n";
}
?>
The above example will output something similar to:
removing sample.blog.posts... gone removing sample.critical.docs... gone removing sample.taxes... gone ...