Helper functions to get a property from an array or object.

get_property.php

<?php
namespace Errthling;

/**
 * Get a property from either an object or an array.
 *
 * @param  string $key The name of the property to retrieve
 * @param  array|object $data The object to retrieve the property for.
 * @return mixed
 */
function get_property( $key, $data ) {
	if ( is_array( $data ) ) {
		return get_array_property( $key, $data );
	} elseif ( is_object( $data ) ) {
		return get_object_property( $key, $data );
	}

	return null;
}

/**
 * Get a property from an array.
 *
 * @param  string $key The name of the property to retrieve
 * @param  array $data The array to retrieve the property for.
 * @return mixed
 */
function get_array_property( $key, $data ) {
	if ( ! isset( $data[ $key ] ) ) {
		return null;
	}

	return $data[ $key ];
}

/**
 * Get a property from an object.
 *
 * @param  string $key The name of the property to retrieve
 * @param  object $data The object to retrieve the property for.
 * @return mixed
 */
function get_object_property( $key, $data ) {
	if ( ! isset( $data->$key ) ) {
		return null;
	}

	return $data->$key;
}