View Full Version : Check if a variable exists
Dalziel
04-10-2003, 04:24 PM
if (FILE_EXISTS)
Is there any way to check "if (VARIABLE_EXISTS)"?
Weirdan
04-10-2003, 04:40 PM
if(isset($var)) do_something();
missing-score
04-10-2003, 05:20 PM
You can just put
if($var)
to check if a variable exists. :thumbsup:
Dalziel
04-10-2003, 05:25 PM
Thanks
brothercake
04-10-2003, 07:37 PM
Originally posted by missing-score
You can just put
if($var)
to check if a variable exists. :thumbsup:
That's only true if you have "~E_NOTICE" in your error handling config. If you are showing notices then you still get a warning for non-existent vars, unless you test for isset()
I don't know for a fact, but I presume that strict coding is more efficient than loose, as it is with JS. Can anyone confirm or refute that?
missing-score
04-10-2003, 07:51 PM
I use strict coding aswell, and I do always use isset(), because it makes it easier to read.
I was just saying that you can test for variables like that. :thumbsup:
Sorry if you misunderstood! Its not my day today :(
If you want to look if the field of a form is filled out you should use the empty-function
if (empty($var))
because the variable is set but the value is NULL
TFP
missing-score
04-10-2003, 10:57 PM
Nice one, I forgot all about empty function. :rolleyes:
firepages
04-11-2003, 04:46 AM
Originally posted by brothercake
I don't know for a fact, but I presume that strict coding is more efficient than loose, as it is with JS. Can anyone confirm or refute that?
Yes , as you say PHP will generate a warning if you go if($var) and $var is undefined.
The fact that PHP has to generate that warning (printed to screen or otherwiase) technically makes the script less efficient, we are talking millisecond or part of I am sure, but true non the less.
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