in reply to Re^3: Variable assignment error checking
in thread Variable assignment error checking

Call the function cough($cough) only if $cough is true?

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Re^5: Variable assignment error checking
by Anonymous Monk on Dec 15, 2013 at 10:13 UTC
[reply]

      It is not! In this expression: 

      $var = func($var) || $var;

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      the return value of func($var) will be assigned to $var if func($var) is true, otherwise the value of $var. In this expression 

      $var ||= func( $var );

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      the return value of func($var) will be assigned to $var if $var is false.

      Completely different logic!

      The expression $var ||= func( $var ); is shorthand for $var = $var || func( $var );. Can you spot the difference?

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[d/l]
[select]
        $var = $var || func( $var );
$var = func( $var ) || $var;

        [download]
        They're certainly logically equivalent if we disregard the short-circuiting nature of operators. (Though the mathematics branch of logic generally deals with no other return values than true and false...)
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[d/l]

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