Programming Forums > Web Development and Design > PHP

Sane · Jan 31st, 2008, 3:31 PM

That's pretty intense...

I only assumed it does. I thought create_function returns a reference to the anonymous function, just as a function name is a reference to a named function.

 PHP Syntax (Toggle Plain Text) 
$newfunc = create_function('$a,$b', 'return "ln($a) + ln($b) = " . log($a * $b);');
echo $newfunc(2, M_E);
$newfunc = create_function('$a,$b', 'return "ln($a) + ln($b) = " . log($a * $b);');
echo $newfunc(2, M_E);

Is equivilent to:

 PHP Syntax (Toggle Plain Text) 
function newfunc ($a,$b) { return "ln($a) + ln($b) = " . log($a * $b); }
echo $newfunc(2, M_E);
function newfunc ($a,$b) { return "ln($a) + ln($b) = " . log($a * $b); }
echo $newfunc(2, M_E);

grimpirate · Jan 31st, 2008, 3:56 PM

Doesn't appear to be possible as I get the following error messages when I tested that little snippet out:
Undefined variable: newfunc in ... on line #
Fatal error: Function name must be a string in ... on line #

grimpirate · Feb 1st, 2008, 10:33 AM

Figured it out Sane, rather than doing it that way you would use call_user_func. So that array_filter_multi would become

 PHP Syntax (Toggle Plain Text) 
function array_filter_multi($array, $callback, $filtered_output = ""){
	$ret = array();
	foreach($array as $key => $value){
		if([i]call_user_func($callback, $key, $value)[/i]){
			if(is_array($value)){
				$ret[$key] = array_filter_multi($value, $callback, $filtered_output);
			}elseif(is_object($value)){
				$ret[$key] = array_filter_multi(get_object_vars($value), $callback, $filtered_output);
			}else{    
				$ret[$key] = $value;
			}
		}else{
			$ret[$key] = $filtered_output;
		}
	}
	return $ret;
}
function array_filter_multi($array, $callback, $filtered_output = ""){
	$ret = array();
	foreach($array as $key => $value){
		if([i]call_user_func($callback, $key, $value)[/i]){
			if(is_array($value)){
				$ret[$key] = array_filter_multi($value, $callback, $filtered_output);
			}elseif(is_object($value)){
				$ret[$key] = array_filter_multi(get_object_vars($value), $callback, $filtered_output);
			}else{    
				$ret[$key] = $value;
			}
		}else{
			$ret[$key] = $filtered_output;
		}
	}
	return $ret;
}

Then you could just write a function such as

 PHP Syntax (Toggle Plain Text) 
function comparator($key, $value){
	return $key < $value;
}
function comparator($key, $value){
	return $key < $value;
}

And finally pass it to the previous function by doing the following

 PHP Syntax (Toggle Plain Text) 
array_filter_multi($data, "comparator", null);
array_filter_multi($data, "comparator", null);

Sane · Feb 1st, 2008, 10:39 AM

I will have to add that to my arsenal of handy functions.

grimpirate · Feb 1st, 2008, 10:40 AM

One final correction it can work the way you said Sane, but it needs one extra step:

 PHP Syntax (Toggle Plain Text) 
function comparator($key, $value){
	return $key < $value;
}
$foo = 'comparator';
print_r($foo(0, 1));
function comparator($key, $value){
	return $key < $value;
}
$foo = 'comparator';
print_r($foo(0, 1));

Sane · Feb 1st, 2008, 10:47 AM

Ah, I see. So it would have worked the way I said, except when I posted:

(Toggle Plain Text)

function callback_func($key, $value) { return ($value < 2 || $value > 70); }

print_r(array_filter_multi($data, $callback_func, null));

It was actually:

(Toggle Plain Text)

function callback_func($key, $value) { return ($value < 2 || $value > 70); }

print_r(array_filter_multi($data, 'callback_func', null));

Jan 31st, 2008, 3:31 PM	#11
Sane Programming Guru Join Date: Apr 2005 Posts: 1,799 Rep Power: 5	Re: Function too convoluted? That's pretty intense... I only assumed it does. I thought create_function returns a reference to the anonymous function, just as a function name is a reference to a named function. PHP Syntax (Toggle Plain Text) $newfunc = create_function('$a,$b', 'return "ln($a) + ln($b) = " . log($a * $b);'); echo $newfunc(2, M_E); $newfunc = create_function('$a,$b', 'return "ln($a) + ln($b) = " . log($a * $b);'); echo $newfunc(2, M_E); Is equivilent to: PHP Syntax (Toggle Plain Text) function newfunc ($a,$b) { return "ln($a) + ln($b) = " . log($a * $b); } echo $newfunc(2, M_E); function newfunc ($a,$b) { return "ln($a) + ln($b) = " . log($a * $b); } echo $newfunc(2, M_E);

Jan 31st, 2008, 3:56 PM	#12
grimpirate King of Portal Join Date: Sep 2005 Posts: 403 Rep Power: 3	Re: Function too convoluted? Doesn't appear to be possible as I get the following error messages when I tested that little snippet out: Undefined variable: newfunc in ... on line # Fatal error: Function name must be a string in ... on line # __________________ Lo, there do I see my father. 'Lo, there do I see My mother, and my sisters, and my brothers. 'Lo, there do I see The line of my people... Back to the beginning. 'Lo, they do call to me. They bid me take my place among them. In the halls of Valhalla... Where the brave... May live... ...forever.. GrimBB \| Mimesis

Feb 1st, 2008, 10:33 AM	#13
grimpirate King of Portal Join Date: Sep 2005 Posts: 403 Rep Power: 3	Re: Function too convoluted? Figured it out Sane, rather than doing it that way you would use call_user_func. So that array_filter_multi would become PHP Syntax (Toggle Plain Text) function array_filter_multi($array, $callback, $filtered_output = ""){ $ret = array(); foreach($array as $key => $value){ if([i]call_user_func($callback, $key, $value)[/i]){ if(is_array($value)){ $ret[$key] = array_filter_multi($value, $callback, $filtered_output); }elseif(is_object($value)){ $ret[$key] = array_filter_multi(get_object_vars($value), $callback, $filtered_output); }else{ $ret[$key] = $value; } }else{ $ret[$key] = $filtered_output; } } return $ret; } function array_filter_multi($array, $callback, $filtered_output = ""){ $ret = array(); foreach($array as $key => $value){ if([i]call_user_func($callback, $key, $value)[/i]){ if(is_array($value)){ $ret[$key] = array_filter_multi($value, $callback, $filtered_output); }elseif(is_object($value)){ $ret[$key] = array_filter_multi(get_object_vars($value), $callback, $filtered_output); }else{ $ret[$key] = $value; } }else{ $ret[$key] = $filtered_output; } } return $ret; } Then you could just write a function such as PHP Syntax (Toggle Plain Text) function comparator($key, $value){ return $key < $value; } function comparator($key, $value){ return $key < $value; } And finally pass it to the previous function by doing the following PHP Syntax (Toggle Plain Text) array_filter_multi($data, "comparator", null); array_filter_multi($data, "comparator", null); __________________ Lo, there do I see my father. 'Lo, there do I see My mother, and my sisters, and my brothers. 'Lo, there do I see The line of my people... Back to the beginning. 'Lo, they do call to me. They bid me take my place among them. In the halls of Valhalla... Where the brave... May live... ...forever.. GrimBB \| Mimesis

Feb 1st, 2008, 10:39 AM	#14
Sane Programming Guru Join Date: Apr 2005 Posts: 1,799 Rep Power: 5	Re: Function too convoluted? I will have to add that to my arsenal of handy functions.

Feb 1st, 2008, 10:40 AM	#15
grimpirate King of Portal Join Date: Sep 2005 Posts: 403 Rep Power: 3	Re: Function too convoluted? One final correction it can work the way you said Sane, but it needs one extra step: PHP Syntax (Toggle Plain Text) function comparator($key, $value){ return $key < $value; } $foo = 'comparator'; print_r($foo(0, 1)); function comparator($key, $value){ return $key < $value; } $foo = 'comparator'; print_r($foo(0, 1)); __________________ Lo, there do I see my father. 'Lo, there do I see My mother, and my sisters, and my brothers. 'Lo, there do I see The line of my people... Back to the beginning. 'Lo, they do call to me. They bid me take my place among them. In the halls of Valhalla... Where the brave... May live... ...forever.. GrimBB \| Mimesis

Feb 1st, 2008, 10:47 AM	#16
Sane Programming Guru Join Date: Apr 2005 Posts: 1,799 Rep Power: 5	Re: Function too convoluted? Ah, I see. So it would have worked the way I said, except when I posted: (Toggle Plain Text) function callback_func($key, $value) { return ($value < 2 \|\| $value > 70); } print_r(array_filter_multi($data, $callback_func, null)); function callback_func($key, $value) { return ($value < 2 \|\| $value > 70); } print_r(array_filter_multi($data, $callback_func, null)); It was actually: (Toggle Plain Text) function callback_func($key, $value) { return ($value < 2 \|\| $value > 70); } print_r(array_filter_multi($data, 'callback_func', null)); function callback_func($key, $value) { return ($value < 2 \|\| $value > 70); } print_r(array_filter_multi($data, 'callback_func', null));

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Programming Forums > Web Development and Design > PHP

Function too convoluted?