Convert column integer values into date expressions

Question

I've a following associative array named $data

Array
(
    [0] => Array
        (
            [transaction_user_id] => 359691e27b23f8ef3f8e1c50315cd506
            [transaction_no] => 19500912050218
            [transaction_total_amount] => 589.00
            [transaction_date] => 1335932419
            [transaction_status] => cancelled
        )

    [1] => Array
        (
            [transaction_user_id] => 9def02e6337b888d6dbe5617a172c18d
            [transaction_no] => 36010512050819
            [transaction_total_amount] => 79.00
            [transaction_date] => 1336476696
            [transaction_status] => cancelled
        )

    [2] => Array
        (
            [transaction_user_id] => 9def02e6337b888d6dbe5617a172c18d
            [transaction_no] => 19020512050820
            [transaction_total_amount] => 299.00
            [transaction_date] => 1336476739
            [transaction_status] => cancelled
        )

    [3] => Array
        (
            [transaction_user_id] => 9def02e6337b888d6dbe5617a172c18d
            [transaction_no] => 27050512050821
            [transaction_total_amount] => 79.00
            [transaction_date] => 1336476927
            [transaction_status] => cancelled
        )

    [4] => Array
        (
            [transaction_user_id] => 8e9050a3646c98342b9ba079fba80982
            [transaction_no] => 12070512050822
            [transaction_total_amount] => 129.00
            [transaction_date] => 1336477032
            [transaction_status] => cancelled
        )

)

and I want to convert the value of key [transaction_date] into user readable format (i.e. mm/dd/yyyy). For that I written the following code in a function which returns the whole array:

 foreach($data as $value)
 {
    $value[transaction_date]=date('d/m/Y',$value[transaction_date]);
 }
    
 return $data;

My problem is I'm getting the same array without changing the value of [transaction_date] for all the array elements. Actually array with updated values for [transaction_date] is expected to be returned.

How can this issue be resolved?

Coming from javascript, this seems like a hard procedure to adapt to php for simple tasks — Mani, Jun 17 '16 at 14:28

Rikesh · Accepted Answer · 2013-03-18T08:24:38.960

118

Change your foreach to something like this, You are not assigning data back to your return variable $data after performing operation on that.

foreach($data as $key => $value)
{
  $data[$key]['transaction_date'] = date('d/m/Y',$value['transaction_date']);
}

Codepad DEMO.

edited Mar 18 '13 at 08:24

answered Mar 18 '13 at 08:00

Rikesh

26,156
14
79
87

7

Updating the foreach variable array within its scope will not alter its value. http://stackoverflow.com/questions/5810168/php-foreach-by-reference-causes-weird-glitch-when-going-through-array-of-objects – Raj Mar 18 '13 at 08:15

score 46 · Answer 2 · answered May 05 '13 at 08:27

46

This will work too!

foreach($data as &$value) {
  $value['transaction_date'] = date('d/m/Y', $value['transaction_date']);
}

Yay for alternatives!

answered May 05 '13 at 08:27

Mulan

129,518
31
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259

4

this is the correct answer .. you need a & - the other way (accepted) is sort of a subtle "hack" - i.e the `accepted answer` by @Rikesh works `indirectly` for reasons that are not obvious, i.e. to many it might look like a) works, but actually b) is happening, when you needed c) all along.. @naomik's answer is the right one "c)" and while "a)" will work it is not the way to go – Mr Heelis Oct 22 '15 at 11:15

score 21 · Answer 3 · edited Jan 08 '20 at 12:43

21

PHP array_walk() function is specifically for altering array.

Try this:

array_walk ( $data, function (&$key) { 
    $key["transaction_date"] = date('d/m/Y',$key["transaction_date"]); 
});

edited Jan 08 '20 at 12:43

Abhishek Pakhare

476
1
4
15

answered Sep 21 '13 at 14:40

SJ00

638
1
6
10

Thanks! I used this in my own case, to change a certain value in an associative array, by slightly modifying it: array_walk($users, function(&$key) { if ($key['name'] == 'John') $key['name'] = 'Jack'; }); In other words, in users array, change user name to Jack, if it is John. – yenren Apr 26 '19 at 06:30

score 9 · Answer 4 · edited Dec 14 '17 at 07:25

9

Use array_walk_recursive function for multi-denominational array.

array_walk_recursive($data, function (&$v, $k) { 
    if($k == 'transaction_date'){ 
        $v = date('d/m/Y',$v); 
    } 
});

edited Dec 14 '17 at 07:25

answered Dec 14 '17 at 07:09

Naveenkumar N

101
1
2

Recursively iterate over a multi religious denomination, got it ^^ – 99linesofcode Jun 20 '19 at 16:19

score 2 · Answer 5 · answered Oct 01 '20 at 03:53

The best approach is using a lambda within "array_walk" native function to make the required changes:

    array_walk($data, function (&$value, $key) {
            if($key == 'transaction_date'){ 
                  $value = date('d/m/Y', $value); 
            }
    });

The value is updated in the array as it's passed with as a reference "&".

score 1 · Answer 6 · answered Jun 17 '19 at 20:43

This a single solution, in where your_field is a field that will set and new_value is a new value field, that can a function or a single value

foreach ($array as $key => $item) {
   $item["your_field"] = "new_value";
   $array[$key] = $item;
}

In your case new_value will be a date() function

score 0 · Answer 7 · answered Mar 18 '13 at 08:02

0

foreach($data as $value)
{
    $value["transaction_date"] = date('d/m/Y',$value["transaction_date"]);
}
return $data;

answered Mar 18 '13 at 08:02

CoBolt

442
2
11

8

This doesn't work because you didn't use `as &$value`! See my answer for details! – Mulan May 05 '13 at 08:29
This doesn't work because, you not set the element in array, with the new value – Ivan Fretes Jun 17 '19 at 19:42

Convert column integer values into date expressions

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