即使定义了函数，也会收到未定义的错误

Question

I have a class(DaySummary*) with a static function that I've created:

public static function recursive_in_array($search, $arr) {
        foreach ($arr as $item) {
            if(is_array($item))
                return recursive_in_array($search, $item);
            elseif($search == $item)
                return true;
        }
        return false;
    }

Within the code in another function (not a static function in the class) I try to use this function by doing:

if(self::recursive_in_array('taanitE', $exceptions))
        echo 'it is';
    else 
        echo 'it isn"t';

But I get an error saying:

Call to undefined function recursive_in_array()

Why do I get this error? The function is clearly defined!

*DaySummary is inherited from DayAnalyzer which is inherited from DayData.

Answer 1

return recursive_in_array($search, $item);

change to

return self::recursive_in_array($search, $item);

Check here for more details : http://php.net/manual/en/language.oop5.static.php