php中的列表数组

Question

I would like to read all files from a directory, and store them in an array of lists. The keys in the array is the starting letter of the filename, and the list contains all names starting with that letter.

Example: key 'a' may contain a1, a2, a3, a4 key 'b' may contain boat.txt, boast.txt, beast.txt

I have the file scan code in place, but am confused about how to use lists in an array in PHP. Can you help with that?

Thanks!

Answer 1

 $first_char = substr($filename, 0, 1); // 'hello.doc' -> 'h'
 $files[$first_char][] = $filename; // add $filename to the $files array under the 'h' key.