Question

Is there a way I can check for whitespace?

For example, I DO NOT want to check for whitespace such as this…

$string = "The dog ran away!"; and have it output Thedogranaway!

I want to check if there if the entry is ALL whitespace and whitespace only?
…and have it output the error!

Basically, I don’t want to be able to enter all whitespace, and still have it do the mysql_query.
Also, is there a way I can strip all the whitespace before the string, and not from the rest of the string?

$string = " "WHITESPACE HERE" The dog ran away!";

if(empty($string) OR $string == " "){ // crappy example of what i'm trying to do
echo "Try again, please enter a message!"; // error
} else {
mysql_query("UPDATE users SET mesg='$string'")or die(mysql_error()); // do something
echo $post;
}

Answer 1

There is also ctype_space (the easiest, imo, and made to do just this, without doing a bunch of unnecessary string manipulation):

$str = "   \r\n   \t  ";
if (ctype_space($str)) {
    echo 'All whitespace';
}
// All whitespace