PHP Validation form detection field is null method _php tips

The example in this article describes a method for verifying that a field is empty in a php check form. Share to everyone for your reference. Specifically as follows:

PHP verifies the form, detects whether the field is empty, and displays an error message when there are fields in the form that are not filled in.

PHP Back-end code, save as: errorcheck.php

The trim () function can remove the front and back space characters in a string

"(ASCII (0x20)), an ordinary spaces.
" \ t "(ASCII 9 (0x09)), tab.
" \ n "(ASCII 0x0A), a new line (line feed).
" \ r "(ASCII (0x0D)), a carriage return.
" \0″ (ASCII 0 (0x00)), the nul-byte.
" \x0b "(ASCII-One (0x0b)), a vertical tab.

I hope this article will help you with your PHP program design.