php - if string contains only '\n'

Question

I'm trying to set empty MySQL fields to NULL if all they contain is a line break.

if ($field === '\n') :
  $sql = "UPDATE table SET field = NULL
  WHERE id = '$id'
  ";
endif;

For some reason, it does not work. I did check the field, it only contains just one linebreak.

What could be a problem?

Maybe it's treating the '\n' as a string literal instead of a line break. — Nora McDougall-Collins, May 26 '20 at 20:30
`'\n'` is a backslash followed by an `n`, `"\n"` is a line break. https://www.php.net/manual/en/language.types.string.php — Sammitch, May 26 '20 at 20:31

score 1 · Accepted Answer · answered May 26 '20 at 20:31

1

Single quotes inhibit escape sequence replacement. Try "\n":

if ($field === "\n") {
  $sql = "UPDATE table SET field = NULL
  WHERE id = '$id'
  ";
}

answered May 26 '20 at 20:31

knittl

1 Answers1