Get a value from a multidimensional array using the dot syntax

config.php

<?php

class Helper
{
	public static function get( $arr, $key, $default=null )
	{	
		@list( $index, $key ) = explode( '.', $key, 2 );
		
		if ( !isset( $arr[$index] ) ) return $default;

		if ( strlen( $key ) > 0 ) return static::get( $arr[$index], $key, $default );

		return isset( $arr[$index] ) ? $arr[$index] : $default;
	}

}

$arr = [
	'db' => 
			[
				'name' => 
					[
						'data' => 'hahaha'
					]
			],
	'age' => '29'
];

echo Helper::get( $arr, 'db.name.data' ); echo '<br>';
echo Helper::get( $arr, 'age' );