old-approach-array-with-key-php

	public function array_with_keys_recursive($array, $keyToRemain){
		$new_arr = [];

		//normal
		$keysToRemain= is_array($keyToRemain)?$keyToRemain:[$keyToRemain];
		foreach( $array as $key_1=>$val_1 )
		{
			if (in_array($key_1,$keysToRemain))
				$new_arr[$key_1]=$val_1;
		}

		//regex (i.e. *->key1->key2)
		$keysToRemain_REGEX = $this->array_only_values_that_contain($keysToRemain,'->');
		foreach($keysToRemain_REGEX as $eachRegex)
		{
			$keysArr= $this->string_to_array($eachRegex, '->');
			foreach( $array as $key_1=>$val_1 )
			{
				if($keysArr[0]==="*" || $keysArr[0]===$key_1){
					if (!is_array($val_1))
					{
						if (empty($keysArr[1]))
							$new_arr[$key_1]=$val_1;
					}
					else{
						foreach ($val_1 as $key_2=>$val_2)
						{
							if($keysArr[1]==="*" || $keysArr[1]===$key_2){
								if (!is_array($val_2))
								{
									if (empty($keysArr[2]))
										$new_arr[$key_1][$key_2]=$val_2;
								}
								else{
									foreach ($val_2 as $key_3=>$val_3)
									{

										if ( $keysArr[2]==="*" || $keysArr[2]===$key_3 )
										{
											if (!is_array($val_3))
											{
												if (empty($keysArr[3]))
													$new_arr[$key_1][$key_2][$key_3]=$val_3;
											}
											else{
												foreach ($val_3 as $key_4=>$val_4)
												{
													if ( $keysArr[3]==="*" || $keysArr[3]===$key_4 )
													{
														$new_arr[$key_1][$key_2][$key_3][$key_4]=$val_4;
													}
												}
											}
										}
									}
								}
							}
						}
					}
				}
			}
		}

		return $new_arr;
	}