How can I create this multidimensional array from a foreach loop?

Question

I cannot wrap my head around this...I have an array that looks like:

    Array
(
    [0] => Array
        (
            [0] => 20120412
            [1] => United States
            [2] => Illinois
            [3] => Marion
            [4] => 2
        )

    [1] => Array
        (
            [0] => 20120412
            [1] => United States
            [2] => Illinois
            [3] => Carbondale
            [4] => 2
        )

    [2] => Array
        (
            [0] => 20120412
            [1] => United States
            [2] => Illinois
            [3] => Carbondale
            [4] => 2
        )
)

I am wanting it to be like:

array("United States" => array("Illinois" => array("Carbondale" => "4")));

So that it takes the Country out, Then the State, then adds together all of the city's numbers.

So far all I have is:

foreach($location_google_data3 as $location_google_data4){
    if($location_google_data4[0]==date("Ymd")){
         $today_visitsbycountry[$location_google_data4[1]]+=$location_google_data4[4];  
    }
}

This gives me an array with the country and number of visits so that I can iterate through it later, but not sure how to proceed with the rest.

If you don't need the date value, I suggest you remove it first. Also what have you done so far? Post your code please otherwise do your homework first. — hakre
– hakre, Commented Apr 13, 2012 at 19:13
Sorry, I have added what code that I have...I can also change the index to get the state or city array, but just not sure how to piece it altogether. — jdgower
– jdgower, Commented Apr 13, 2012 at 19:18

Dutchie432 · Accepted Answer · 2012-04-13 19:31:16Z

1

Something like this...

$result=array();
foreach ($a as $item)
    $result[$item[1]][$item[2]][$item[3]]+=$item[4];

edited Apr 13, 2012 at 19:31

answered Apr 13, 2012 at 19:20

Dutchie432

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7 Comments

sberry Over a year ago

This is probably solvable, pretty easily, but ++ won't work, as it doesn't just need an incrementor, it needs to be incremented by the value in the array.

Josh Over a year ago

Instead of = 0, it should be = $item[4], and instead of ++ it should be += $item[4]. The result should not be initialized to 0 because it begins with an initial value.

Dutchie432 Over a year ago

Yes, these changes have been made.

Dutchie432 Over a year ago

Im not really sure what you want. it would have worked in just about any form I had on here. Vote, don't vote, thats fine :)

Dutchie432 Over a year ago

Yes, there are better ways of doing everything. This is a demonstration, and will yield the correct result. Some warnings are more serious that others.

|

jnrbsn · Accepted Answer · 2012-04-13 19:21:01Z

1

This is how I would do it (assuming your array is called $input):

$output = array();

foreach ($input as $city) {
    if (!isset($output[$city[1]])) {
        $output[$city[1]] = array();
    }

    if (!isset($output[$city[1]][$city[2]])) {
        $output[$city[1]][$city[2]] = array();
    }

    if (isset($output[$city[1]][$city[2]][$city[3]])) {
        $output[$city[1]][$city[2]][$city[3]] += $city[4];
    } else {
        $output[$city[1]][$city[2]][$city[3]] = $city[4];
    }
}

answered Apr 13, 2012 at 19:21

jnrbsn

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Comments

Michael Harroun · Accepted Answer · 2012-04-13 19:22:58Z

1

$resultArray = array();
foreach($yourArray as $data)
{
    if(!isset($resultArray[$data[1]])) {
        $resultArray[$data[1]] = array();
    }

    if(!isset($resultArray[$data[1]][$data[2]])) {
        $resultArray[$data[1]][$data[2]] = array();
    }

    if(!isset($resultArray[$data[1]][$data[2]][$data[3]])) {
        $resultArray[$data[1]][$data[2]][$data[3]] = 0;
    }

    $resultArray[$data[1]][$data[2]][$data[3]] += $data[4];
}

answered Apr 13, 2012 at 19:22

Michael Harroun

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4 Comments

Josh Over a year ago

Should be initialized to $data[4], not 0.

sberry Over a year ago

Not if he is adding $data[4] on the next line, regardless.

Josh Over a year ago

@sberry That is true. I take it back. :)

hakre Over a year ago

too much work. PHP handles array access on the fly, you don't need to check for each index, you can isset check for the whole index at once.

hakre · Accepted Answer · 2012-04-13 19:36:35Z

1

You do this by picking the values from the array, use them as keys for the new array and then add the number. This example uses a variable alias (reference), so the long version of the variable needs only written once:

$filterDate = '20120412';
$build = array();
foreach ($array as $item)
{
    list($date, $country, $state, $city, $number) = $item;
    if ($date != $filterDate) continue;
    $alias = &$build[$country][$state][$city];
    $alias += $number;
}
unset($alias);

Outcome ($build):

array(1) {
  ["United States"]=>
  array(1) {
    ["Illinois"]=>
    array(2) {
      ["Marion"]=>
      int(2)
      ["Carbondale"]=>
      int(4)
    }
  }
}

answered Apr 13, 2012 at 19:36

hakre

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Comments

Alon Eitan · Accepted Answer · 2012-04-13 19:21:08Z

0

I hope this will work, if not - something like this will do the trick:

$result = array();
foreach( $your_array as $arr ) {
    if( !isset( $result[ $arr[1] ] ) ) {
        $result[ $arr[1] ] = array();
    }
    if( !isset( $result[ $arr[1] ][ $arr[2] ] ) ) {
        $result[ $arr[1] ][ $arr[2] ] = array();
    }
    if( !isset( $result[ $arr[1] ][ $arr[2] ][ $arr[3] ] ) ) {
        $result[ $arr[1] ][ $arr[2] ][ $arr[3] ] = 0;
    }
    $result[ $arr[1] ][ $arr[2] ][ $arr[3] ] += (int)$arr[4];
}

answered Apr 13, 2012 at 19:21

Alon Eitan

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