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[nycphp-talk] Boolean evaluation (PHP vs Java)

Tim Gales tgales at tgaconnect.com
Tue Jan 15 12:14:25 EST 2008


paul at devonianfarm.com wrote:
>[...]
> One of the most controversial features of languages such 
 > as PHP and Perl is the lax evaluation of boolean values
If you look at
http://nyphp.org/phundamentals/variableevaluation.php

You will see a table which shows how variables can be tested.

Beneath the table the article says:
"This table demonstrates somewhat surprising results..."

It talks about "... 0 (the integer), FALSE, and NULL..."
The article also mentions that you have to take into
account variables which are unset (even though unset is
not a variable in a strict sense)

To me this is somewhat like in a database query
which selects from a column (attribute) which can
contain nulls. You have to add 'and column != NULL'
in order to take into account the fact that the
data is not guaranteed to be a strictly 'either/or'
situation.

-- 

T. Gales & Associates
'Helping People Connect with Technology'

http://www.tgaconnect.com



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