On 2 January 2015 21:31:50 GMT+00:00, Wan Chaowei <weiqk@xxxxxxxxxxx> wrote: > > > > >website: http://5go.cc/ >QR Code Generator: http://5go.cc/QRCodeGenerator >"Jim Giner" 写入消息 news:D1.99.60454.91F55A45@xxxxxxxxxxxx... > >On 1/1/2015 3:28 AM, 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 >> >1 - tells you if a var is defined >2 - tells you if the var is null or not yet defined. No, empty() determines if a variable is defined and has a value that is not null, an empty string, the value false, a 0 or "0", or an empty array. >3 - using this as an 'if' condition tells you whether a var is 'not >equal' to null > >plz more note false, null, 0, and empty string, in this case the are >same It checks foremostly that $a is not an empty string, but if $a is not a string the type conversion in PHP takes place. For strict comparison use !== > >BTW - all of this can be found in the manual online. You should spend >the time to read some of the introductory items. Thanks, Ash -- PHP General Mailing List (http://www.php.net/) To unsubscribe, visit: http://www.php.net/unsub.php
