Dumping many variables in PHP

Question

I assure this is a very common situation when you have to test variables (and they are many!), just like this example (I only named vars like this for less-effort-writing sake):

    $variable0='red';
    $variable1='blue';
    $variable2='green';
    $variable3='pink';
    $variable4='purple';
    $variable5='hellow';
    $variable6='foo';
    $variable7='bar';
    $variable8='hi';
    $variable9='bye';

    echo
    '$variable0='.$variable0.'<br>
$variable1='.$variable1.'<br>
$variable2='.$variable2.'<br>
$variable3='.$variable3.'<br>
$variable4='.$variable4.'<br>
$variable5='.$variable5.'<br>
$variable6='.$variable6.'<br>
$variable7='.$variable7.'<br>
$variable8='.$variable8.'<br>
$variable9='.$variable9;

My question is: is there a better way to make this echoing / dumping / printing easier?

Of course, there are other ways of doing the very same presidiary work:

        $x=
    '$variable0='."$variable0\n".
    '$variable1='."$variable1\n".
    '$variable2='."$variable2\n".
    '$variable3='."$variable3\n".
    '$variable4='."$variable4\n".
    '$variable5='."$variable5\n".
    '$variable6='."$variable6\n".
    '$variable7='."$variable7\n".
    '$variable8='."$variable8\n".
    '$variable9='."$variable9"
    echo nl2br($x);

Or:

    $x=<<<HEREDOC
\$variable1=$variable1
\$variable2=$variable2
\$variable3=$variable3
\$variable4=$variable4
\$variable5=$variable5
\$variable6=$variable6
\$variable7=$variable7
\$variable8=$variable8
\$variable9=$variable9;
HEREDOC;
    echo nl2br($x);

But maybe PHP has a function to make this easier?

By the way, all 3 solutions above echoes the very same:

$variable1=blue<br>
$variable2=green<br>
$variable3=pink<br>
$variable4=purple<br>
$variable5=hellow<br>
$variable6=foo<br>
$variable7=bar<br>
$variable8=hi<br>
$variable9=bye;

Answer 1

Introducing compact:

var_dump(compact('foo', 'bar', 'baz'));

Note though that I explicitly used three very different variables: $foo, $bar and $baz.
If you actually do literally have $foo1, $foo2 etc, you're really really looking to use an array instead. Dumping that would be trivial too:

$foo    = array();
$foo[0] = 'bar';
$foo[1] = 'baz';
var_dump($foo);

In general, if you have too many variables floating around, your scope is probably too big and you should refactor everything into a number of smaller functions, or your algorithm is more complex than it needs to be, or you should be using arrays or other data structures instead.

Answer 2

get_defined_vars() would be able to do so. Might be overkill (all accessable vars will be shown):

print_r( get_defined_vars() );

Return Values: A multidimensional array with all the defined variables*.
*In a function it will only show the local $vars, and those defined as global.

Note: This does exactly what you're looking for, but the array methods mentioned in other answers would be a better fit logical-wise, see below:

---

A better way for you to set the values is with an array, this way you 'group' multiple values together:

$color[] = 'red'; // will automatically start with key=0
$color[] = 'blue'; // key=1
$color[] = 'green';// key=2 etc
print_r( $color );
echo $color[1]; // Blue, same as your echo $variable1;

Answer 3

You can declare your variables as keys from an array instead

$myarray=Array();

$myarray['variable0']='red';
$myarray['variable1']='blue';
$myarray['variable2']='green';
$myarray['variable3']='pink';
$myarray['variable4']='purple';
$myarray['variable5']='hellow';
$myarray['variable6']='foo';
$myarray['variable7']='bar';
$myarray['variable8']='hi';
$myarray['variable9']='bye';

and print them all with

echo '<pre>';
print_r($myarray);
echo '</pre>';

then, in case you still need to use them as separate variables, doing

extract($myarray)

will create $variable0 to $variable9 in the global context.

Answer 4

If you know the upper and lower bounds and all the variables have a similar name you could do the following:

for ($i = 0; $i < $end; ++$i) { echo ${'value_name'. $i}; }

Answer 5

Try refactor your code and use arrays

Then you can do print_r or var_dump

Answer 6

This should give you the output your looking for:

function get_var_name($var) {
    foreach($GLOBALS as $var_name => $value) {
        if ($value === $var) {
            return $var_name;
        }
    }

    return "Variable name not found";
}

function miracle_var_dump($valuesToDump) {

    //For each variable in the $valuesToDump array, print the name and value
    for($i = 0; $i < count($valuesToDump); $i++) {
        echo(get_var_name($valuesToDump[i]) . "=" . $valuesToDump[i] . "<br/>");
    }

}

//Making a call to dump the variables
miracle_var_dump(array($variable0,$variable1,$variable2,$variable3,$variable4,$variable5,$variable6,$variable7,$variable8,$variable9))

Function get_var_name gets the variable name given the variable (taken from one of Jeremey Rutins awsners).

Answer 7

//let your variables like this
$variable0='red';
$variable1='blue';
$variable2='green';

//an array to keep all the variable names
$var_names=array();
$var_names[]='$variable0';
$var_names[]='$variable1';
$var_names[]='$variable2';
//etc...

print_var_name($var_names);

function print_var_name($var_names) {
//loop through the array and dump them if they are in $GLOBALS
foreach($GLOBALS as $var_name => $value) {
    if (in_array('$'.$var_name,$var_names)) {
        echo $var_name;
        var_dump($value);
    }
}