PHP uses recursive and non recursive methods to create multi-level folders

Project requirements ： Recursive creation is required AA/BB/CC/DD Folder ; The code implementation is as follows ：

function makeDir($dir) {
    
	//  First determine whether the parent directory exists , If it doesn't exist , Create an upper level directory 
	$prev = dirname($dir);
	if (!file_exists($prev)) {
    
		//  Create an upper level directory 
		makeDir($prev);
	}
	//  The upper level directory was created successfully , Create the current directory 
	mkdir($dir);
}
makeDir('AA/BB/CC/DD');

Methods that do not use recursion can use PHP Self contained function ： mkdir(‘dir1/dir2/dir3’, 0777, true);
Note that this notation only supports PHP5.5 Above version