What is wrong with this syntax while using ( condition ? true : false )??? 1

[southbeach]

I have code such as

$blank='';
$string = '
<td>
<input name="itemName" id="itemName" type="text" size="12" maxlength="20" 
value="'.isset($line['name'])?$line['name']:$blank.'" />
</td>';

It is not working! Why?



--
SouthBeach

http://www.fpgroups.com

The good thing about not knowing is the opportunity to learn - Yours truly, 2008.

 

[southbeach]

Well, I went right back to my code and changed it to

$blank='';
$string = '
<td>
<input name="itemName" id="itemName" type="text" size="12" maxlength="20" 
value="'.(isset($line['name'])?$line['name']:$blank).'" />
</td>';

I wrapped the condition within parenthesis and it works now ... I do not see why this makes such a difference ...


--
SouthBeach

http://www.fpgroups.com

The good thing about not knowing is the opportunity to learn - Yours truly, 2008.

 

[feherke]

Hi

I wrapped the condition within parenthesis and it works now ... I do not see why this makes such a difference ...

It is because the Operator Precedence : concatenation has higher priority than the ternary operator.

So without parenthesis the concatenations get evaluated first :

$string=[highlight #fcc]'before'.'condition'[/highlight]?[highlight #cfc]'truevalue'[/highlight]:[highlight #ccf]'falsevalue'.'after'[/highlight];

[gray]// same as[/gray]

$string=[highlight #fcc]'beforecondition'[/highlight]?[highlight #cfc]'truevalue'[/highlight]:[highlight #ccf]'falsevalueafter'[/highlight];

Feherke.
feherke.github.io

 

[southbeach]

Goes to show that you are taught the very basic things for a very basic reason!

Thanks,


--
SouthBeach

http://www.fpgroups.com

The good thing about not knowing is the opportunity to learn - Yours truly, 2008.