Multi Dimensional Array to Single Deminsional Array

single.php

<?php

function multi_to_single_r( $array ){
	
	foreach( $array as $key => $value ){
		
		if( is_array( $value ) ){
			
			unset( $array[ $key ] );
			
			$value = multi_to_single_r( $value );
			
			$array = array_merge( $array, $value );
		}
	}
	
	return $array;
}

$array = array(
	'aye',
	array(
		'bee',
		array(
			'sea'
		)
	)
);

$array = multi_to_single_r( $array );

echo "<pre>";
var_dump( $array );
echo "</pre>";