function to output multiple variable names, getting the name of a var into a string

JFrankParnell

Hi,

$mice = array('mickey','minni','mighty');
$pets = array('cow'=>'bessie','dog'=>'fido','mice' => $mice);
$config = 'some setting';

function showvars($message){
$args = func_get_args();
echo"<pre>"; print_r($args);echo"</pre>";
echo "$message <BR>";
foreach ($args as $k=>$v) {
$name = var_name($k,get_defined_vars());
echo '$'.$name.' = '.$v."<br>";
}
}

function var_name (&$iVar, &$aDefinedVars){
foreach ($aDefinedVars as $k=>$v){
$aDefinedVars_0[$k] = $v;
}
$iVarSave = $iVar;
$iVar =!$iVar;

$aDiffKeys = array_keys (array_diff_assoc ($aDefinedVars_0, $aDefinedVars));
$iVar      = $iVarSave;

return $aDiffKeys[0];

}

echo var_name($mice,get_defined_vars())."<br>";// output: mice (as expected)
echo showvars('heres the vars:',$pets,$config);

the goal here is to have showvars() output something like:
here's the vars:
$pets = array
$config = some setting

thanks for your time,
J

Weedpacket

Huh?

But you won't have much luck. The name of a variable and its value are two different things (for one thing, multiple variables can refer to the same value), and it's the value that is passed to a function. The called function can't know what the caller function is using as the name of the variable in which it stored its reference to the value that it passed.

Besides, what would happen if I wrote "showvars(42)"?

JFrankParnell

k, i got this working, please let me know if there is a better way (not having to pass get_defined_vars(). $gdv = get_defined_vars() wouldnt work for me);

function dumpvars($message){
	$args = func_get_args();
	for ($i = 1; $i <= count($args); $i++) {
		foreach ($args[$i] as $k=>$v ){
			$vars[$k] = $v;
		}
	}
	$out = "/* \n".$message." \n */ \n ";
	foreach ($vars as $k=>$v) {
		$out .= ' $'.$k.' = '.var_export($v,true).";\n ";
	}
return $out;
}
function var_name (&$iVar, &$aDefinedVars){
    foreach ($aDefinedVars as $k=>$v)
        $aDefinedVars_0[$k] = $v;

$iVarSave = $iVar;
$iVar     =!$iVar;

$aDiffKeys = array_keys (array_diff_assoc ($aDefinedVars_0, $aDefinedVars));
$iVar      = $iVarSave;
 return array($aDiffKeys[0]=>$iVar);
 }


$mice = array('mickey','minni','mighty');
$pets = array('cow'=>'bessie','dog'=>'fido','mice' => $mice);
$config = 'some setting';

$filename = 'heres your vars:';
$out =  dumpvars($filename,var_name($pets,get_defined_vars()),var_name($config,get_defined_vars()));

unset($vars,$pets,$config);

echo "<HR><PRE>";	
echo htmlentities($out);
echo "<HR></PRE>";	

eval( $out );

echo "<HR><PRE>";	
print_r($pets);
print_r($config);
echo "<HR></PRE>";

Weedpacket

var_name($pets,get_defined_vars())

It's still not clear to me: if you already know the name of the variable is $pets, why do you need to go to any hassle to find out that the name of the variable is $pets?

But I tried your code and got

Notice: Undefined offset:  3 in C:\test.php on line 5

Call Stack:
    0.0012   1. {main}() C:\test.php:0
    0.0016   2. dumpvars() C:\test.php:33


Warning: Invalid argument supplied for foreach() in C:\test.php on line 5

Call Stack:
    0.0012   1. {main}() C:\test.php:0
    0.0016   2. dumpvars() C:\test.php:33

(I'm guessing that "<=count" should be "<count") before getting some code equivalent to the output of

function dumpvars($message, $vars){
	echo "/*\n$message\n*/\n";
	foreach($vars as $name=>$var)
	{
		echo dump($name, $var);
	}
}

function dump($name, $value)
{
	return '$'.$name.' = '.var_export($value,true).";\n";
}



$pets = array('cow'=>'bessie','dog'=>'fido','mice' => array('mickey','minni','mighty'));
$config = 'some setting';

$header = "Here are your vars:";
dumpvars($header, array('pets'=>$pets, 'config'=>$config));

Of course neither of these handle situations where the variable is something like $foo->bar[42].

JFrankParnell

It's still not clear to me: if you already know the name of the variable is $pets, why do you need to go to any hassle to find out that the name of the variable is $pets?

because i want a function that i can pass any number of vars to. I'm actually doing a little more than what you see in dumpvars(), which is a simplified version of my actual func.

Of course, your funcs work, and for any implementation i can think of right now, off the bat, they would be fine. Thanks!

Weedpacket

Well get_defined_vars() is kind of inevitable if you don't want to pass each name and its value separately: each function has its own scope, and variables aren't shared between them by name.

function dumpvars($defined_vars)
{
	$vars = func_get_args();
	array_shift($vars);
	$dumped_vars = array_intersect_key($defined_vars, $vars);
	foreach($dumped_vars as $name=>$value)
	{
		....
	}
}


$foo = 42;
$bar = array('this'=>'that');
$bax = "Some other thing";
dumpvars(get_defined_vars(), 'foo', 'bar', 'baz', ....);

But the example I had earlier could easily be extended to allow passing 'name', $name, 'foo', $foo, 'bar', $bar, ....

JFrankParnell

nice, but i had to insert an array_flip in there:

function dumpvars2($defined_vars){
    $vars = func_get_args();
    array_shift($vars);
    $vars = array_flip($vars);
    $dumped_vars = array_intersect_key ($defined_vars, $vars);
    foreach($dumped_vars as $name=>$value){
        echo "<br />\${$name}=".var_export($value,true);
    }
}


$foo = 42;
$bar = array('this'=>'that');
$bax = "Some other thing";
dumpvars2(get_defined_vars(), 'foo', 'bar', 'bax'); 

//	$foo=42
//	$bar=array ( 'this' => 'that', )
//	$bax='Some other thing'

does that look right to you?

Weedpacket

Oh yes; I didn't test it at all; the array_flip is necessary. (I think it might be because I was initially going to pass everything that was to be dumped as array('name'=>$name....) in order to avoid passing get_defined_vars as well. But then that's not really much different from passing names and variables as individual arguments (although simpler to deal with).