| Re: Why Can't I "define" a Value for a Subscript? [message #175262 is a reply to message #175260] |
Tue, 30 August 2011 15:09  |
Jerry Stuckle
Messages: 2598
Registered: September 2010
Karma:
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Senior Member |
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On 8/30/2011 9:55 AM, A.Reader wrote:
> On Sun, 28 Aug 2011 15:18:32 -0400,
> "eBob.com"<eBob(dot)com(at)totallybogus(dot)com> wrote:
>
>> I am working with some csv files. To make the program more maintainable and
>> more self-documenting I "define" values to use as subscripts; e.g. ...
>>
>> define('SS2KEY',0);
>>
>> BUT, whereas this produces what I expected ...
>>
>> echo "we have a match - key: $file2cols[0]\n";
>>
>> ... this does not ...
>>
>> echo "we have a match - key: $file2cols[SS2KEY]\n";
>>
>> I see the other text but no value is substitited for $file2cols[SS2KEY]
>>
>> I've wasted so much time on this. Why can't I define constants to use as
>> subscripts?
>
> Suggestion: don't use double quotes except when you want some
> control char such as "\n" interpreted. You get some other
> interpretation 'for free', but it's almost never really for free,
> as others have indicated.
>
> A better way is to use single quotes around the string bits and
> leave non-string bits 'raw', gluing everything together with the
> string-concat operator (.). So your example would work fine if
> you did it this way:
>
> echo 'we have a match - key: '.$file2cols[SS2KEY].'<br>' ;
>
> echo will evaluate vars and consts correctly without needing any
> garnish as long as they're not inside a string.
>
> Hope that helps.
That's one way to do it. But a lot of people, myself included, detest
the complete mishmash such coding creates. I think the following is
much clearer:
echo "we have a match - key: {$file2cols[SS2KEY]}<br>";
And fewer quotes means less chance of mismatched quotes, which can still
happen even with an intelligent editor.
Another way (which I like less but has its uses) would be:
printf('we have a match - key: %s<br>', $file2cols[SS2KEY]);
This can be handy when you have a lot of values, some of them being the
result of function calls (i.e. mysql_real_escape_string()).
--
==================
Remove the "x" from my email address
Jerry Stuckle
JDS Computer Training Corp.
jstucklex(at)attglobal(dot)net
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