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How create an array from the output of an array printed with print_r?

Posted by: admin November 30, 2017 Leave a comment

Questions:

I have an array:

$a = array('foo' => 'fooMe');

and I do:

print_r($a);

which prints:

Array ( [foo] => printme )

Is there a function, so when doing:

needed_function('    Array ( [foo] => printme )');

I will get the array array('foo' => 'fooMe'); back?

Answers:

I actually wrote a function that parses a “stringed array” into an actual array. Obviously, it’s somewhat hacky and whatnot, but it works on my testcase. Here’s a link to a functioning prototype at http://codepad.org/idlXdij3.

I’ll post the code inline too, for those people that don’t feel like clicking on the link:

<?php
     /**
      * @author ninetwozero
      */
?>
<?php
    //The array we begin with
    $start_array = array('foo' => 'bar', 'bar' => 'foo', 'foobar' => 'barfoo');

    //Convert the array to a string
    $array_string = print_r($start_array, true);

    //Get the new array
    $end_array = text_to_array($array_string);

    //Output the array!
    print_r($end_array);

    function text_to_array($str) {

        //Initialize arrays
        $keys = array();
        $values = array();
        $output = array();

        //Is it an array?
        if( substr($str, 0, 5) == 'Array' ) {

            //Let's parse it (hopefully it won't clash)
            $array_contents = substr($str, 7, -2);
            $array_contents = str_replace(array('[', ']', '=>'), array('#!#', '#?#', ''), $array_contents);
            $array_fields = explode("#!#", $array_contents);

            //For each array-field, we need to explode on the delimiters I've set and make it look funny.
            for($i = 0; $i < count($array_fields); $i++ ) {

                //First run is glitched, so let's pass on that one.
                if( $i != 0 ) {

                    $bits = explode('#?#', $array_fields[$i]);
                    if( $bits[0] != '' ) $output[$bits[0]] = $bits[1];

                }
            }

            //Return the output.
            return $output;

        } else {

            //Duh, not an array.
            echo 'The given parameter is not an array.';
            return null;
        }

    }
?>

Questions:
Answers:

If you want to store an array as string, use serialize [docs] and unserialize [docs].

To answer your question: No, there is no built-in function to parse the output of print_r into an array again.

Questions:
Answers:

No. But you can use both serialize and json_* functions.

$a = array('foo' => 'fooMe');
echo serialize($a);

$a = unserialize($input);

Or:

echo json_encode($a);

$a = json_decode($input, true);

Questions:
Answers:

For Array output with Subarrays, the solution provided by ninetwozero will not work, you can try with this function that works with complex arrays:

<?php

$array_string = "

Array
 (
   [0] => Array
    (
       [0] => STATIONONE
       [1] => 02/22/15 04:00:00 PM
       [2] => SW
       [3] => Array
            (
                [0] => 4.51
            )

        [4] => MPH
        [5] => Array
            (
                [0] => 16.1
            )

        [6] => MPH
    )

     [1] => Array
    (
        [0] => STATIONONE
        [1] => 02/22/15 05:00:00 PM
        [2] => S
        [3] => Array
            (
                [0] => 2.7
            )

        [4] => MPH
        [5] => Array
            (
                [0] => 9.61
            )

        [6] => MPH
    )
)
";

print_r(print_r_reverse(trim($array_string)));

function print_r_reverse(&$output)
{
    $expecting = 0; // 0=nothing in particular, 1=array open paren '(', 2=array element or close paren ')'
    $lines = explode("\n", $output);
    $result = null;
    $topArray = null;
    $arrayStack = array();
    $matches = null;
    while (!empty($lines) && $result === null)
    {
        $line = array_shift($lines);
        $trim = trim($line);
        if ($trim == 'Array')
        {
            if ($expecting == 0)
            {
                $topArray = array();
                $expecting = 1;
            }
            else
            {
                trigger_error("Unknown array.");
            }
        }
        else if ($expecting == 1 && $trim == '(')
        {
            $expecting = 2;
        }
        else if ($expecting == 2 && preg_match('/^\[(.+?)\] \=\> (.+)$/', $trim, $matches)) // array element
        {
            list ($fullMatch, $key, $element) = $matches;
            if (trim($element) == 'Array')
            {
                $topArray[$key] = array();
                $newTopArray =& $topArray[$key];
                $arrayStack[] =& $topArray;
                $topArray =& $newTopArray;
                $expecting = 1;
            }
            else
            {
                $topArray[$key] = $element;
            }
        }
        else if ($expecting == 2 && $trim == ')') // end current array
        {
            if (empty($arrayStack))
            {
                $result = $topArray;
            }
            else // pop into parent array
            {
                // safe array pop
                $keys = array_keys($arrayStack);
                $lastKey = array_pop($keys);
                $temp =& $arrayStack[$lastKey];
                unset($arrayStack[$lastKey]);
                $topArray =& $temp;
            }
        }
        // Added this to allow for multi line strings.
    else if (!empty($trim) && $expecting == 2)
    {
        // Expecting close parent or element, but got just a string
        $topArray[$key] .= "\n".$line;
    }
        else if (!empty($trim))
        {
            $result = $line;
        }
    }

    $output = implode("\n", $lines);
    return $result;
}

/**
* @param string $output : The output of a multiple print_r calls, separated by newlines
* @return mixed[] : parseable elements of $output
*/
function print_r_reverse_multiple($output)
{
    $result = array();
    while (($reverse = print_r_reverse($output)) !== NULL)
    {
        $result[] = $reverse;
    }
    return $result;
}

?>

There is one tiny bug, if you have an empty value (empty string) it gets embedded in the value before.

Questions:
Answers:

you cannot do this with print_r,
var_export should allow something similar, but not exactly what you asked for

http://php.net/manual/en/function.var-export.php

$val = var_export($a, true);
print_r($val);
eval('$func_val='.$val.';');

Questions:
Answers:

There’s an online tool that can help
http://www.printr-reverse.org/

It does a decent job but misses commas after sub-arrays and maybe other places so a little manual fix should do the job.