On Thu, 2015-01-01 at 13:58 +0530, Sachin Raut wrote: > Happy New Year to all members of PHP group. > > I just want to know the difference between following 3 statements. Or are > they all does the same thing. > > 1. isset($a) > 2. !empty($a) > 3. $a!="" > > Thanks > Sachin Happy new year to yourself as well! Each of these is similar, but subtly different: 1. isset() checks to see if a variable exists, and doesn't care if it has a value or not. 2. empty() checks to see if both the variable exists and the value doesn't equate to the boolean false, an empty string, the number/string 0, null, or an empty array. 3. $a != "" just checks to see if $a equates to an empty string, note though that PHP has loose typing, so if $a isn't a string, it's converted to one internally just for the purposes of the comparison. If you have to specifically check for the empty string, then !== might be better. There is one more that you didn't mention, which is is_null(), and that one checks to see if a variable contains a null value, which is covered by empty() but is a bit more specific (you may want a variable to be a 0, but you want to check it's not null before you try and use it, for example) Hope this helps. -- Thanks, Ash http://www.ashleysheridan.co.uk -- PHP General Mailing List (http://www.php.net/) To unsubscribe, visit: http://www.php.net/unsub.php
