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

Question

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?

Answer 1

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;
        }

    }
?>

Answer 2

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.

Answer 3

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);

Answer 4

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.';');

Answer 5

There is a nice Online-Tool which does exatly what its name is:

print_r to json online converter

From a JSON Object its not far to creating an array with the json_decode function:

To get an array from this, set the second paramter to true. If you don't, you will get an object instead.

json_decode($jsondata, true);

Answer 6

I think my function is cool too, works with nested arrays:

function print_r_reverse($input)
{
    $output = str_replace(['[', ']'], ["'", "'"], $input);
    $output = preg_replace('/=> (?!Array)(.*)$/m', "=> '$1',", $output);
    $output = preg_replace('/^\s+\)$/m', "),\n", $output);
    $output = rtrim($output, "\n,");
    return eval("return $output;");
}

NB: better not use this with user input data

Answer 7

Here is a print_r output parser, producing the same expression in PHP syntax. It is written as an interactive Stack Snippet, so you can use it here:

function parse(s) {
    const quote = s => '"' + s.replace(/["\\]/g, '\\$&') + '"';
    const compress = indent => " ".repeat(((indent.length + 4) >> 3) * 4);
    return "$data = " + (s.replace(/\r\n?/g, "\n") + "\n").replace(
        /(Array|\w+ (Object)) *\n *\( *\n|^( *)(?:\[(?:(0|-?[1-9]\d*)|(.*?))\] => |(\) *\n+))|(-?\d+(?:\.\d+)?(?:E[-+]\d+)?)\n|(.*(?:\n(?! *\) *$| *\[.*?\] => ).*)*)\n/gm,
        (_, array, object, indent, index, key, close, number, string) => 
            object ? "(object) [\n"
                   : array ? "[\n"
                           : close ? compress(indent) + "],\n"
                                   : indent ? compress(indent) + (index ?? quote(key)) + " => "
                                            : (number ?? quote(string)) + ",\n"
    ).replace(/,\n$/, ";");
}

// I/O handling
const [input, output] = document.querySelectorAll("textarea");
(input.oninput = () => output.value = parse(input.value))();

textarea { width: 23em; height: 12em }

<table><tr><th>Input print_r format</th><th>Output PHP syntax</th></tr>
<tr><td><textarea>
Array
(
    [0] => example
    [1] => stdClass Object
        (
            [a[] => 1.43E+19
            ["] => quote
            [] => 
        )
)
</textarea></td><td><textarea readonly></textarea></td></tr></table>

Remarks

• Don't remove any line breaks from the original print_r output. For instance, both the opening and closing parentheses after Array must appear on separate lines.
• Don't change the spacing around => (one space before, one after).
• As print_r does not distinguish between null, "" or false (it produces no output for these values), nor between true and 1 (both are output as 1), this converter will never produce null, false or true.
• As print_r does not distinguish between numbers and strings (9 could represent a number or a string), this converter will assume that the data type is to be numeric when such ambiguity exists.
• stdClass Object is supported and translates to (object) [...] notation
• MyClass Object will be treated as if it was a stdClass object.
• String literals in the output are double quoted and literal double quotes and backslashes are escaped.

Answer 8

Quick function (without checks if you're sending good data):

function textToArray($str)
{
    $output = [];

    foreach (explode("\n", $str) as $line) {

        if (trim($line) == "Array" or trim($line) == "(" or trim($line) == ")") {
            continue;
        }

        preg_match("/\[(.*)\]\ \=\>\ (.*)$/i", $line, $match);

        $output[$match[1]] = $match[2];
    }

    return $output;
}

This is the expected input:

Array
(
    [test] => 6
)

Answer 9

This is how I interpreted the question:

function parsePrintedArray($s){
    $lines = explode("\n",$s);
    $a = array();
    foreach ($lines as $line){
        if (strpos($line,"=>") === false)
            continue;
        $parts = explode('=>',$line);
        $a[trim($parts[0],'[] ')] = trim($parts[1]);
    }
    return $a;
}

Works for both objects and arrays:

$foo = array (
    'foo' => 'bar',
    'cat' => 'dog'
);

$s = print_r($foo,1);
$a = parsePrintedArray($s);
print_r($a);

Output:

Array
(
    [foo] => bar
    [cat] => dog
) 

doesnt work on nested arrays, but simple and fast.

Answer 10

use

var_export(array('Sample array', array('Apple', 'Orange')));

Output:

array (
  0 => 'Sample array',
  1 => 
  array (
    0 => 'Apple',
    1 => 'Orange',
  ),
)

Answer 11

json_encode() and json_decode() function will do it.

$asso_arr = Array([779] => 79 => [780] => 80 [782] => 82 [783] => 83);
$to_string = json_encode($asso_arr);

It will be as a json format {"779":"79","780":"80","782":"82","783":"83"}

Then we will convert it into json_decode() then it gives associative array same as original:

print_r(json_decode($to_string));

Output will be Array([779] => 79 => [780] => 80 [782] => 82 [783] => 83) in associative array format.