note 109419 deleted from function.is-bool by danbrown

Note Submitter: Matt Kantor ---- @ kim at steinhaug dot com I recently needed a "sloppy" boolean conversion function similar to yours. I felt a bit uncomfortable using hard-coded truthy/falsy strings (after all, the list could go on forever), so I wrote my own: <?php function loosely_cast_to_boolean($value) { if(is_array($value) || $value instanceof Countable) { return (boolean) count($value); } else if(is_string($value) || is_object($value) && method_exists($value, '__toString')) { $value = (string) $value; // see http://www.php.net/manual/en/filter.filters.validate.php#108218 $filtered = filter_var($value, FILTER_VALIDATE_BOOLEAN, FILTER_NULL_ON_FAILURE); if(!is_null($filtered)) { return $filtered; } else { // "none" gets special treatment to be consistent with ini file behavior. // see documentation in php.ini for more information, in part it says: // "An empty string can be denoted by simply not writing anything after // the equal sign, or by using the None keyword". if(strtolower($value) === 'none') { $value = ''; } return (boolean) $value; } } else { return (boolean) $value; } } ?> Note that for objects which are both countable and string-castable, this will favor the count over the string value to determine truthiness. That is, if <?php $object instanceof Countable ?> this will return <?php (boolean) count($object) ?> regardless of the value of <?php (string) $object ?>. You can see the behavior for the test data I used as well as the results for several other functions (including your [kim's] version) here: http://codepad.viper-7.com/ErfNQ5 . It's kind of hard to skim the results from that little iframe, so you can view the script output in a full page, instead: http://codepad.viper-7.com/ErfNQ5/5.4.0 (this URL is undocumented so it might not work forever). The line between what "ought to be true" and what oughtn't is pretty arbitrary; the data I used is categorized based on my needs and aesthetic preferences, yours may differ.