how to stop error if variable not found

[iammudassir]

i have a text field like this <td width="62"> < input name="delivery_no[]" type="text" size="5" value = " <?php if(isset($_POST['select'])) // i set value here for this field { echo $rows[3]['delivery_no']; // this echo $rows is coming from a sql query } ?>"/></td> problem is that if my sql query has this result it echo here BUT when my sql query has no result my page generate an error i just required if my sql query does not have this $rows[0] my field remains blank and i can continue work on other fields. like thisif sql query has $rows[3] echo it other wise do nothing let field blank

[niche]

What's that vertical rectangle in your input field name?

[birbal]

You can use issset() to determine if any variable exist or not. if exist then show up it. if you want to know your query is really returning rows or not, you can mysql_num_rows() or equivalant method of other api(mysqli/pdo)

What's that vertical rectangle in your input field name?

It is not rectangle, it is open and closed square bracets of array notation.

[iammudassir]

You can use issset() to determine if any variable exist or not. if exist then show up it. if you want to know your query is really returning rows or not, you can mysql_num_rows() or equivalant method of other api(mysqli/pdo) It is not rectangle, it is open and closed square bracets of array notation.

can you tell me please how to to set isset to check if variable is present please note i already set if isset $_POST['select']

[iammudassir]

can you tell me how to set isset to check if variable is present or not with submit buttonlike this i want this type of code if select button is press check $a is present if present echo $a

[thescientist]

http://php.net/manual/en/function.isset.php

[satishpoul]

if(isset($_POST['select'])){ if(isset($a)) { echo $a; }}

[iammudassir]

if(isset($_POST['select'])){ if(isset($a)) { echo $a; }}

thank you for correct replycan we use && here instead of using two time IF if yes then how i wanna use && operator like thisif(isset($_POST['select'])) && if(isset($a)) ???? what wrong with this code

[satishpoul]

yahh if((isset(..)) && (isset(..)) && (another conditions...))

[satishpoul]

don't use if in condition of another if.. like u didif(... && if() ... )

[iammudassir]

don't use if in condition of another if.. like u didif(... && if() ... )

ok thank you sooooo much

[birbal]

isset() also accpets multiplr value. where the all the passed variable must have to set to return a TRUE. it is similar to using isset() with conjugation with && in 'if-else' structure. http://w3schools.invisionzone.com/index.php?showtopic=45820&view=findpost&p=255803 also you can read more about control structure and operators herehttp://php.net/language..operator.conditionalhttp://php.net/language.control_structure