diff --git a/.gitignore b/.gitignore
new file mode 100644
index 0000000..af1f417
--- /dev/null
+++ b/.gitignore
@@ -0,0 +1,2 @@
+composer.lock
+/vendor
diff --git a/Collection.php b/Collection.php
new file mode 100644
index 0000000..5e76ec1
--- /dev/null
+++ b/Collection.php
@@ -0,0 +1,803 @@
+<?php
+/**
+ * A PHP utility class for manipulating collections.
+ *
+ * @package wpscholar\Collection
+ */
+
+namespace wpscholar;
+
+/**
+ * Class Collection
+ *
+ * @package wpscholar
+ */
+class Collection implements \ArrayAccess, \Countable, \IteratorAggregate, \JsonSerializable {
+
+	/**
+	 * The items contained in the collection.
+	 *
+	 * @var array
+	 */
+	protected $items = [];
+
+	/**
+	 * Collection constructor.
+	 *
+	 * @param array $items Initial collection items
+	 */
+	public function __construct( array $items = [] ) {
+		$this->items = $items;
+	}
+
+	/**
+	 * Static method for creating a collection.
+	 *
+	 * @param array $items Initial collection items
+	 *
+	 * @return static
+	 */
+	public static function make( array $items = [] ) {
+		return new static( $items );
+	}
+
+	/**
+	 * Get all of the items in the collection.
+	 *
+	 * @return array
+	 */
+	public function all() {
+		return $this->items;
+	}
+
+	/**
+	 * Push all of the given items onto the collection.
+	 *
+	 * @param array $items Items to add to the collection
+	 *
+	 * @return $this
+	 */
+	public function concat( array $items ) {
+		$collection = new static( $this->all() );
+		foreach ( $items as $item ) {
+			$collection->push( $item );
+		}
+
+		return $collection;
+	}
+
+	/**
+	 * Determine if an item exists in the collection.
+	 *
+	 * @param mixed $key Item for which to check
+	 *
+	 * @param bool  $strict Whether or not to use a strict comparison
+	 *
+	 * @return bool
+	 */
+	public function contains( $key, $strict = true ) {
+		return in_array( $key, $this->items, $strict );
+	}
+
+	/**
+	 * Get the total number of items in the collection.
+	 *
+	 * @return int
+	 */
+	public function count() {
+		return count( $this->items );
+	}
+
+	/**
+	 * Get the items in the collection that are not present in the given items.
+	 *
+	 * @param  array $items Items to exclude
+	 *
+	 * @return static
+	 */
+	public function diff( array $items ) {
+		return new static( array_diff( $this->items, $items ) );
+	}
+
+	/**
+	 * Execute a callback over each item.
+	 *
+	 * @param  callable $callback Callback to be mapped to each item
+	 *
+	 * @return $this
+	 */
+	public function each( callable $callback ) {
+		foreach ( $this->items as $key => $item ) {
+			$callback( $item, $key );
+		}
+
+		return $this;
+	}
+
+	/**
+	 * Get all items except for those with the specified keys.
+	 *
+	 * @param array|string $keys Key(s) to exclude
+	 *
+	 * @return static
+	 */
+	public function except( $keys ) {
+		$keys = (array) $keys;
+
+		return $this->filter(
+			function ( $key, $value ) use ( $keys ) {
+				return ! in_array( $key, $keys, true );
+			}
+		);
+	}
+
+	/**
+	 * Run a filter over each of the items.
+	 *
+	 * @param callable|null $callback Filter callback
+	 *
+	 * @return static
+	 */
+	public function filter( callable $callback = null ) {
+		if ( null === $callback ) {
+			return new static( array_filter( $this->items ) );
+		}
+
+		return new static( array_filter( $this->items, $callback, ARRAY_FILTER_USE_BOTH ) );
+	}
+
+	/**
+	 * Get the first item from the collection.
+	 *
+	 * @return mixed
+	 */
+	public function first() {
+		return $this->slice( 0, 1 )->shift();
+	}
+
+	/**
+	 * Flip the items in the collection.
+	 *
+	 * @return static
+	 */
+	public function flip() {
+		return new static( array_flip( $this->items ) );
+	}
+
+	/**
+	 * Remove one or more items from the collection by key.
+	 *
+	 * @param  string|array $keys Key(s) to exclude
+	 *
+	 * @return $this
+	 */
+	public function forget( $keys ) {
+		foreach ( (array) $keys as $key ) {
+			$this->offsetUnset( $key );
+		}
+
+		return $this;
+	}
+
+	/**
+	 * "Paginate" the collection by slicing it into a smaller collection.
+	 *
+	 * @param  int $page Page number
+	 * @param  int $perPage Number of items per page
+	 *
+	 * @return static
+	 */
+	public function forPage( $page, $perPage ) {
+		$offset = max( 0, ( $page - 1 ) * $perPage );
+
+		return $this->slice( $offset, $perPage );
+	}
+
+	/**
+	 * Get an item from the collection by key.
+	 *
+	 * @param mixed $key Key used to find item
+	 * @param mixed $default Default value to return if item doesn't exist
+	 *
+	 * @return mixed
+	 */
+	public function get( $key, $default = null ) {
+
+		$value = $default;
+
+		if ( $this->offsetExists( $key ) ) {
+			$value = $this->items[ $key ];
+		}
+
+		return $value;
+	}
+
+	/**
+	 * Get an iterator for the items.
+	 *
+	 * @return \ArrayIterator
+	 */
+	public function getIterator() {
+		return new \ArrayIterator( $this->items );
+	}
+
+	/**
+	 * Group an associative array by a field.
+	 *
+	 * @param callable|string $groupBy Property or index to group by
+	 *
+	 * @return static
+	 */
+	public function groupBy( $groupBy ) {
+
+		$results = [];
+		foreach ( $this->items as $item ) {
+			if ( is_array( $item ) && array_key_exists( $groupBy, $item ) ) {
+				$results[ $item[ $groupBy ] ][] = $item;
+			} elseif ( is_object( $item ) && property_exists( $item, $groupBy ) ) {
+				$results[ $item->{$groupBy} ][] = $item;
+			}
+		}
+
+		return new static( $results );
+	}
+
+	/**
+	 * Determine if one or more items exist in the collection by key.
+	 *
+	 * @param mixed $key Key for which to check
+	 *
+	 * @return bool
+	 */
+	public function has( $key ) {
+		$keys = is_array( $key ) ? $key : func_get_args();
+		foreach ( $keys as $value ) {
+			if ( ! $this->offsetExists( $value ) ) {
+				return false;
+			}
+		}
+
+		return true;
+	}
+
+	/**
+	 * Concatenate values of a given key as a string.
+	 *
+	 * @param string $glue String used to join the items
+	 *
+	 * @return string
+	 */
+	public function implode( $glue = null ) {
+		return implode( $glue, $this->items );
+	}
+
+	/**
+	 * Index an associative array by a field.
+	 *
+	 * @param callable|string $indexBy Property or index used to index.
+	 *
+	 * @return static
+	 */
+	public function indexBy( $indexBy ) {
+
+		$results = [];
+		foreach ( $this->items as $item ) {
+			if ( is_array( $item ) && array_key_exists( $indexBy, $item ) ) {
+				$results[ $item[ $indexBy ] ] = $item;
+			} elseif ( is_object( $item ) && property_exists( $item, $indexBy ) ) {
+				$results[ $item->{$indexBy} ] = $item;
+			}
+		}
+
+		return new static( $results );
+	}
+
+	/**
+	 * Insert a value or key/value pair after a specific key in an array.  If key doesn't exist, value is appended
+	 * to the end of the array.
+	 *
+	 * @param mixed $key The key after which the items will be inserted
+	 * @param array $value An array containing the key(s) and value(s) to be inserted
+	 *
+	 * @return $this
+	 */
+	public function insertAfter( $key, array $value ) {
+
+		if ( ! $this->has( $key ) ) {
+			return $this->push( $value );
+		}
+
+		$index       = array_search( $key, array_keys( $this->items ), true );
+		$pos         = false === $index ? count( $this->items ) : $index + 1;
+		$this->items = array_merge( array_slice( $this->items, 0, $pos ), $value, array_slice( $this->items, $pos ) );
+
+		return $this;
+	}
+
+	/**
+	 * Insert a value or key/value pair before a specific key in an array.  If key doesn't exist, value is prepended
+	 * to the beginning of the array.
+	 *
+	 * @param mixed $key The key before which the items will be inserted
+	 * @param array $value An array containing the key(s) and value(s) to be inserted
+	 *
+	 * @return $this
+	 */
+	public function insertBefore( $key, array $value ) {
+
+		if ( ! $this->has( $key ) ) {
+			return $this->prepend( $value );
+		}
+
+		$pos         = (int) array_search( $key, array_keys( $this->items ), true );
+		$this->items = array_merge( array_slice( $this->items, 0, $pos ), $value, array_slice( $this->items, $pos ) );
+
+		return $this;
+	}
+
+	/**
+	 * Intersect the collection with the given items.
+	 *
+	 * @param array $items Items with which to intersect
+	 *
+	 * @return static
+	 */
+	public function intersect( array $items ) {
+		return new static( array_intersect( $this->items, $items ) );
+	}
+
+	/**
+	 * Intersect the collection with the given items by key.
+	 *
+	 * @param array $keys Keys with which to intersect
+	 *
+	 * @return static
+	 */
+	public function intersectByKeys( array $keys ) {
+		return new static( array_intersect_key( $this->items, $keys ) );
+	}
+
+	/**
+	 * Convert the object into something JSON serializable.
+	 *
+	 * @return array
+	 */
+	public function jsonSerialize() {
+		return $this->items;
+	}
+
+	/**
+	 * Get the keys of the collection items.
+	 *
+	 * @return static
+	 */
+	public function keys() {
+		return array_keys( $this->items );
+	}
+
+	/**
+	 * Get the last item from the collection.
+	 *
+	 * @return mixed
+	 */
+	public function last() {
+		return $this->slice( - 1, 1 )->pop();
+	}
+
+	/**
+	 * Run the map over each of the items.
+	 *
+	 * @param callable $callback Callback to map to each item
+	 *
+	 * @return static
+	 */
+	public function map( callable $callback ) {
+		$keys  = array_keys( $this->items );
+		$items = array_map( $callback, $this->items, $keys );
+
+		return new static( array_combine( $keys, $items ) );
+	}
+
+	/**
+	 * Merge the collection with the given items.
+	 *
+	 * @param  array $items Items to merge
+	 *
+	 * @return static
+	 */
+	public function merge( array $items ) {
+		return new static( array_merge( $this->items, $items ) );
+	}
+
+	/**
+	 * Determine if an item exists at an offset.
+	 *
+	 * @param mixed $key Key for which to check
+	 *
+	 * @return bool
+	 */
+	public function offsetExists( $key ) {
+		return array_key_exists( $key, $this->items );
+	}
+
+	/**
+	 * Get an item at a given offset.
+	 *
+	 * @param mixed $key Key used to find item
+	 *
+	 * @return mixed
+	 */
+	public function offsetGet( $key ) {
+		return $this->items[ $key ];
+	}
+
+	/**
+	 * Set the item at the given offset.
+	 *
+	 * @param mixed $key Key to set
+	 * @param mixed $value Value to set
+	 */
+	public function offsetSet( $key, $value ) {
+		if ( null === $key ) {
+			$this->items[] = $value;
+		} else {
+			$this->items[ $key ] = $value;
+		}
+	}
+
+	/**
+	 * Unset the item at a given offset.
+	 *
+	 * @param mixed $key Key to unset
+	 */
+	public function offsetUnset( $key ) {
+		unset( $this->items[ $key ] );
+	}
+
+	/**
+	 * Get the items with the specified keys.
+	 *
+	 * @param array $keys Keys to fetch
+	 *
+	 * @return static
+	 */
+	public function only( $keys ) {
+		return $this->filter(
+			function ( $key, $value ) use ( $keys ) {
+				return in_array( $key, $keys, true );
+			}
+		);
+	}
+
+	/**
+	 * Get the values of a given key.
+	 *
+	 * @param  string|array|null $key Key to fetch
+	 * @param  string|null       $indexKey Key to use as index
+	 *
+	 * @return static
+	 */
+	public function pluck( $key, $indexKey = null ) {
+		return new static( array_column( $this->items, $key, $indexKey ) );
+	}
+
+	/**
+	 * Get and remove the last item from the collection.
+	 *
+	 * @return mixed
+	 */
+	public function pop() {
+		return array_pop( $this->items );
+	}
+
+	/**
+	 * Push an item onto the beginning of the collection.
+	 *
+	 * @param  mixed $value Value to prepend
+	 *
+	 * @return $this
+	 */
+	public function prepend( $value ) {
+		array_unshift( $this->items, $value );
+
+		return $this;
+	}
+
+	/**
+	 * Get and remove an item from the collection.
+	 *
+	 * @param mixed $key Key by which to fetch
+	 * @param mixed $default Value to return if item doesn't exist
+	 *
+	 * @return mixed
+	 */
+	public function pull( $key, $default = null ) {
+		$value = $this->get( $key, $default );
+		$this->offsetUnset( $key );
+
+		return $value;
+	}
+
+	/**
+	 * Push an item onto the end of the collection.
+	 *
+	 * @param mixed $value Item to append
+	 *
+	 * @return $this
+	 */
+	public function push( $value ) {
+		$this->offsetSet( null, $value );
+
+		return $this;
+	}
+
+	/**
+	 * Put an item in the collection by key.
+	 *
+	 * @param mixed $key Key to set
+	 * @param mixed $value Value to set
+	 *
+	 * @return $this
+	 */
+	public function put( $key, $value ) {
+		$this->offsetSet( $key, $value );
+
+		return $this;
+	}
+
+	/**
+	 * Get one or a specified number of items randomly from the collection.
+	 *
+	 * @param int $count Number of items to return
+	 *
+	 * @return static
+	 */
+	public function random( $count = 1 ) {
+		$values = [];
+		$keys   = (array) array_rand( $this->items, min( $count, $this->count() ) );
+		foreach ( $keys as $key ) {
+			$values[ $key ] = $this->offsetGet( $key );
+		}
+
+		return new static( $values );
+	}
+
+	/**
+	 * Reverse items order.
+	 *
+	 * @return static
+	 */
+	public function reverse() {
+		return new static( array_reverse( $this->items, true ) );
+	}
+
+	/**
+	 * Search the collection for a given value and return the corresponding key if successful.
+	 *
+	 * @param mixed $value Value by which to search
+	 * @param bool  $strict Whether or not to use a strict comparison
+	 *
+	 * @return mixed
+	 */
+	public function search( $value, $strict = false ) {
+		return array_search( $value, $this->items, $strict );
+	}
+
+	/**
+	 * Get and remove the first item from the collection.
+	 *
+	 * @return mixed
+	 */
+	public function shift() {
+		return array_shift( $this->items );
+	}
+
+	/**
+	 * Shuffle the items in the collection.
+	 *
+	 * @return static
+	 */
+	public function shuffle() {
+		return new static( shuffle( $this->items ) );
+	}
+
+	/**
+	 * Slice the underlying collection array.
+	 *
+	 * @param int $offset Numeric offset
+	 * @param int $length Length of returned collection
+	 *
+	 * @return static
+	 */
+	public function slice( $offset, $length = null ) {
+		return new static( array_slice( $this->items, $offset, $length, true ) );
+	}
+
+
+	/**
+	 * Sort through each item with a callback.
+	 *
+	 * @param callable|null $callback Callback used for sorting
+	 *
+	 * @return static
+	 */
+	public function sort( callable $callback = null ) {
+		$items = $this->items;
+		$callback ? uasort( $items, $callback ) : asort( $items );
+
+		return new static( $items );
+	}
+
+	/**
+	 * Sort the collection keys.
+	 *
+	 * @param int  $options Can be SORT_REGULAR (0), SORT_NUMERIC (1), SORT_STRING (2), SORT_LOCALE_STRING (5)
+	 * @param bool $descending True to sort descending, false to sort ascending
+	 *
+	 * @return static
+	 */
+	public function sortKeys( $options = SORT_REGULAR, $descending = false ) {
+		$items = $this->items;
+		$descending ? krsort( $items, $options ) : ksort( $items, $options );
+
+		return new static( $items );
+	}
+
+	/**
+	 * Take the first or last {$limit} items.
+	 *
+	 * @param int $limit Number of items to return (negative number returns last items, positive returns first items)
+	 *
+	 * @return static
+	 */
+	public function take( $limit ) {
+		if ( $limit < 0 ) {
+			return $this->slice( $limit, abs( $limit ) );
+		}
+
+		return $this->slice( 0, $limit );
+	}
+
+	/**
+	 * Pass the collection to the given callback and then return it.
+	 *
+	 * @param callable $callback Callback to use
+	 *
+	 * @return $this
+	 */
+	public function tap( callable $callback ) {
+		$callback( new static( $this->items ) );
+
+		return $this;
+	}
+
+	/**
+	 * Get the collection of items as an array.
+	 *
+	 * @return array
+	 */
+	public function toArray() {
+		return $this->all();
+	}
+
+	/**
+	 * Get the collection of items as JSON.
+	 *
+	 * @param int $options Can be JSON_PRETTY_PRINT or other such constants.
+	 *
+	 * @return string
+	 */
+	public function toJson( $options = 0 ) {
+		return json_encode( $this->jsonSerialize(), $options );
+	}
+
+	/**
+	 * Convert the collection to its string representation.
+	 *
+	 * @return string
+	 */
+	public function toString() {
+		return $this->toJson();
+	}
+
+	/**
+	 * Transform each item in the collection using a callback.
+	 *
+	 * @param callable $callback Callback to use
+	 *
+	 * @return $this
+	 */
+	public function transform( callable $callback ) {
+		$this->items = $this->map( $callback )->all();
+
+		return $this;
+	}
+
+	/**
+	 * Return only unique items from the collection array.
+	 *
+	 * @return static
+	 */
+	public function unique() {
+		return new static( array_unique( $this->items ) );
+	}
+
+	/**
+	 * Reset the keys on the underlying array.
+	 *
+	 * @return static
+	 */
+	public function values() {
+		return array_values( $this->items );
+	}
+
+	/**
+	 * Apply the callback if the value is truthy. Otherwise, call the fallback (if set).
+	 *
+	 * @param bool     $value Evaluated conditional
+	 * @param callable $callback Callback to apply
+	 * @param callable $fallback Fallback value to return
+	 *
+	 * @return mixed
+	 */
+	public function when( $value, callable $callback, callable $fallback = null ) {
+		return $value ? $callback( $this, $value ) : ( $fallback ? $fallback( $this, $value ) : $this );
+	}
+
+	/**
+	 * Filter items by the given key value pair.
+	 *
+	 * @param string $key Key to fetch
+	 * @param mixed  $operator Operator to use
+	 * @param mixed  $value Value to check
+	 *
+	 * @return static
+	 */
+	public function where( $key, $operator, $value = null ) {
+
+		if ( func_num_args() === 2 ) {
+			$value    = $operator;
+			$operator = '=';
+		}
+
+		return $this->filter(
+			function ( $item ) use ( $key, $operator, $value ) {
+
+				$retrieved = isset( $item[ $key ] ) ? $item[ $key ] : null;
+
+				switch ( $operator ) {
+					default:
+					case '=':
+					case '==':
+						return $retrieved == $value;
+					case '!=':
+					case '<>':
+						return $retrieved != $value;
+					case '<':
+						return $retrieved < $value;
+					case '>':
+						return $retrieved > $value;
+					case '<=':
+						return $retrieved <= $value;
+					case '>=':
+						return $retrieved >= $value;
+					case '===':
+						return $retrieved === $value;
+					case '!==':
+						return $retrieved !== $value;
+				}
+
+			}
+		);
+	}
+
+	/**
+	 * Convert the collection to its string representation.
+	 *
+	 * @return string
+	 */
+	public function __toString() {
+		return $this->toString();
+	}
+
+}
diff --git a/composer.json b/composer.json
new file mode 100644
index 0000000..699d838
--- /dev/null
+++ b/composer.json
@@ -0,0 +1,17 @@
+{
+  "name": "wpscholar/collection",
+  "description": "A PHP utility class for manipulating collections.",
+  "type": "library",
+  "license": "GPL-2.0-or-later",
+  "authors": [
+    {
+      "name": "Micah Wood",
+      "email": "micah@wpscholar.com"
+    }
+  ],
+  "autoload": {
+    "psr-4": {
+      "wpscholar\\": ""
+    }
+  }
+}
diff --git a/readme.md b/readme.md
new file mode 100644
index 0000000..1540d16
--- /dev/null
+++ b/readme.md
@@ -0,0 +1,3 @@
+# Collection
+
+A PHP utility class for manipulating collections.