PHP array_merge_recursive with numeric keys

Question

So I'm suppose to build a multidimensional array dynamically from a text file, and everything works perfectly except that the numeric keys are screwing me over...

The text file looks something like this:

a=1
b.c=2
b.d.0.e=3
b.d.0.f=4
b.d.1.e=5
b.d.1.f=6

As the array_merge_recursive doesn't work with numeric keys, the output is like:

array(2) { 
 ["a"]=>  
 string(3) "1" 
 ["b"]=>  
 array(2) { 
  ["c"]=>  
  string(3) "2" 
  ["d"]=>  
  array(4) { 
   [0]=>  
   array(1) { 
    ["e"]=>  
    string(9) "3" 
   } 
   [1]=>  
   array(1) { 
    ["f"]=>  
    string(4) "4" 
   } 
   [2]=>  array(1) { 
    ["e"]=>  
    string(8) "5" 
   } 
   [3]=>  
   array(1) { 
    ["f"]=>  
    string(9) "6" 
 }}}}

Is there any easy solution to make the output like...?

array(2) { 
 ["a"]=>  
 string(3) "1" 
 ["b"]=>  
 array(2) {
  ["c"]=>  
  string(3) "2" 
  ["d"]=>  
  array(2) { 
   [0]=>  
   array(2) { 
    ["e"]=>  
    string(9) "3" 
    ["f"]=>  
    string(4) "4"  
   } 
   [1]=>  
   array(3) { 
    ["e"]=>  
    string(9) "5"
    ["f"]=>  
    string(4) "6"
}}}}

Thanks

Any of the solutions in the answers will work, but I'd suggest to whomever is storing the data like this that it be done more appropriately (for example, using json strings). — GZipp
– GZipp, Commented Jan 12, 2010 at 15:15

nickf · Accepted Answer · 2010-01-12 13:57:42Z

3

You could break each bit into its components and build up the array one step at a time.

$path = "b.d.0.e";
$val = 3;
$output = array();

$parts = explode(".", $path);

// store a pointer to where we currently are in the array.
$curr =& $output;

// loop through up to the second last $part
for ($i = 0, $l = count($parts); $i < $l - 1; ++$i) {
    $part = $parts[$i];

    // convert numeric strings into integers
    if (is_numeric($part)) {
        $part = (int) $part;
    }

    // if we haven't visited here before, make an array
    if (!isset($curr[$part])) {
        $curr[$part] = array();
    }

    // jump to the next step
    $curr =& $curr[$part];
}

// finally set the value
$curr[$parts[$l - 1]] = $val;

My output, using the same input as yours:

Array (
    [a] => 1
    [b] => Array (
        [c] => 2
        [d] => Array (
            [0] => Array (
                [e] => 3
                [f] => 4
            )
            [1] => Array (
                [g] => 5
                [h] => 6
            )
        )
    )
)

edited Jan 12, 2010 at 13:57

answered Jan 12, 2010 at 13:50

nickf

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1 Comment

per_pilot Over a year ago

Thanks for a good answer :) The if(is_numeric) isn't needed though, I think it already interprets the var as an int.

GZipp · Accepted Answer · 2010-01-12 14:35:45Z

0

Or you could use eval():

$raw_data = file($txt_file, FILE_IGNORE_NEW_LINES);
foreach ($raw_data as $line) {
    list($keys, $value) = explode('=', $line);
    $keys = explode('.', $keys);
    $arr_str = '$result';
    foreach ($keys as $key) {
        if (ctype_digit($key)) {
            $arr_str .= "[" . $key . "]";
        } else {
            $arr_str .= "['" . $key . "']";
        }
    }
    eval($arr_str . ' = $value;');
}

print_r($result);

edited Jan 12, 2010 at 14:35

answered Jan 12, 2010 at 14:26

GZipp

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Comments

John B · Accepted Answer · 2014-11-20 21:47:24Z

0

I know this is an old one, but the best solution I have found is to use array_replace_recursive. It will achieve what you are looking to do:

$start = array(
   "600" => array("total" => 100),
   "700" => array("total" => 200)
);

$finish = array(
  "600" => array("average" => 25),
  "700" => array("average" => 50)
);

$out = array_replace_recursive($start,$finish);
var_dump($out):

array(2) {
  [600]=>
  array(2) {
    ["total"]=>
    int(100)
    ["average"]=>
    int(25)
  }
  [700]=>
  array(2) {
    ["total"]=>
    int(200)
    ["average"]=>
    int(50)
  }
}

answered Nov 20, 2014 at 21:47

John B

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