possible reason for the output.

abstract class theBase
{
	function theFunc($min,$max)
	{
		$func=function($value)
		{
			$increase=function(&$var)
			{
				$var++;
				return ($var+2);
			};
			return ($increase($value));
		};
		return (array_map($func,range($min,$max)));
	}
}

class theChild extends theBase
{
	function doMoreWork(&$var)
	{
		$var++;
                return($var+3);
	}
}

$theClass=new theChild;
$theArray=call_user_func_array(array($theClass,"theFunc"),array(3,5,7));
array_walk($theArray,array($theClass,"doMoreWork"));
print_r($theArray);

PHP:

the output is :7,8,9

Can someone help why 7,8,9 and not 11,12,13 .In doMoreWork function ($var+3) is showing no effect why? Can someone help to understand this behavior.

 

Well first when I look at $increase, &$var has no purpose as array_map() is simply calling $func for every value in the range($min,$max) = range(3,5). With each new call, $var is in it's own scope (has a different memory address) so a parameter of $var would not differ from &$var in this case.

For theChild::doMoreWork(), return $var+3 has no affect as array_walk()'s first parameter is &array(). Thus the values of &array will be changed according to $var in theChild::doMoreWork(), the first (and only) parameter. What you have is really the same as:

abstract class theBase
{
    function theFunc($min,$max)
    {
        $func=function($value)
        {
            $increase=function($var)
            {
                return ($var+3);
            };
            return ($increase($value));
        };
        return (array_map($func,range($min,$max)));
    }
}

class theChild extends theBase
{
    function doMoreWork(&$var)
    {
        $var++;
    }
}

$theClass=new theChild;
$theArray=call_user_func_array(array($theClass,"theFunc"),array(3,5));
array_walk($theArray,array($theClass,"doMoreWork"));
print_r($theArray);

PHP: