PHP learning some summary

• The file upload

  In the foreground of the <form> MAX_FILE_SIZE form hidden hidden field control can play a substantial role, that is, before you can upload files to determine the file size, format:

. 1 <form Action = "" Method = "the POST" the enctype = "multipart / form-Data">
 2      <INPUT type = "hidden" name = "The MAX_FILE_SIZE" value = "10485760">
 . 3      <-! Note that this value place value is not 1024 * 1024 * 10 format ->
 . 4 </ form>

I began to think this thing is futile, only to discover later upload the file if given the wrong error code is 2 time, the problem lies in this place