How to sort date array in php?

Question

I am new to php, I have php date array

[0] => 11-01-2012
[1] => 01-01-2014
[2] => 01-01-2015
[3] => 09-02-2013
[4] => 01-01-2013

I want to sort it like :

[0] => 11-01-2012
[1] => 01-01-2013
[2] => 09-02-2013
[3] => 01-01-2014
[4] => 01-01-2015

I use asort but not working.

Answer 1

If the date is in "Mysql" format (Y-m-d or Y-m-d H:i:s), then you can sort your array right away, no special action needed:

$arr = ["2019-11-11", "2019-10-10","2019-11-11", "2019-09-08","2019-05-11"];
sort($arr);

If the date is localized or formatted anyhow (that you should avoid, formatting the date only before output) you have to use a custom sorting function, such as usort(), that will convert the dates into sortable format before comparison.

The simplest way to convert a date into sortable format is to convert it into uninx timestamp using strtotime() function:

$arr = ['11/01/2012', '03/16/2022', '12/26/2021', '01/01/2014', '09/02/2013'];
usort($arr, function ($a, $b) {
    return strtotime($a) - strtotime($b);
});
print_r($arr);

Check result in demo

However, there could be pitfalls, because in different countries the same date format could mean a different date. Which is exactly the case with your example format, for which the above function will return wrong results if dates are ['03-16-2022', '12-26-2021', '06-06-2022']. Therefore it's better to define the date format explicitly, as explained in this answer

Answer 2

The example dates data provided aren't clear what format they are. To be sure, you should use DateTime::createFromFormat and then specify the format explicitly:

$dates = ['11-01-2012', '03-16-2022', '12-26-2021', '01-01-2014', '01-01-2015', '09-02-2013', '01-01-2013'];

function sort_date($a, $b) {
    return \DateTime::createFromFormat('m-d-Y', $a) <=> \DateTime::createFromFormat('m-d-Y', $b);
}

usort($dates, "sort_date");

Answer 3

Try below code:

<?php 

$array = array('11-01-2012','01-01-2011','09-02-2013','01-01-2014','01-01-2015');

function cmp($a, $b)
{
    $a = date('Y-m-d', strtotime($a));
    $b = date('Y-m-d', strtotime($b));

    if ($a == $b) {
        return 0;
    }
    return ($a < $b) ? -1 : 1;
}
usort($array, "cmp");

foreach ($array as $key => $value) {
    echo "[$key]=> $value <br>";
}
?>

Answer 4

out of the box use time function to generate ts and sort

<?php
  $out = array();
  // $your_array is the example obove
  foreach($your_array as $time) {
  $out[strtotime($time)] = $time;
  }
  // now $out has ts-keys and you can handle it

  ...
 ?>

ksort

Answer 5

Try this,

<?php 
$array = [ '11-01-2012', '01-01-2014', '01-01-2015', '09-02-2013', '01-01-2013' ];
function sortFunction( $a, $b ) {
    return strtotime($a) - strtotime($b);
}
usort($array, "sortFunction");
var_dump( $array );
?>

Will sort the dates into the order you want.

Answer 6

I solved this problem by applying this line.

sort($imdarrayGG['newDate']);

Output before adding the value

[Mon Jul  6 10:33:23 2020] Array
(
    [coursedate] => 2020-07-17
    [newDate] => Array
        (
            [0] => 2020-07-30
            [1] => 2020-07-07
            [2] => 2020-07-08
            [3] => 2020-07-17
        )

)

After I put the line, the output will become like this.

[Mon Jul  6 10:35:42 2020] Array
(
    [coursedate] => 2020-07-17
    [newDate] => Array
        (
            [0] => 2020-07-07
            [1] => 2020-07-08
            [2] => 2020-07-17
            [3] => 2020-07-30
        )

)

The date already sorted which is the latest date will be at the up.

This is where we have object and then we want to sort all of them

Example:-

[status_custom] => Array
    (
        [0] => stdClass Object
            (
                [type] => LDL - B2
                [date] => 23/10/2014
            )

        [1] => stdClass Object
            (
                [type] => LDL - D
                [date] => 18/04/2015
            )
   )

First we have to convert. Refer to this link to convert And then we sort them. Refer to this link to sort object

Here we go:-

    //At here we want to sort according to latest date. But this one involve with the object also.
    usort($array_custom_object, function ($a, $b) {
        $date1 = $a->date;
        $date2 = $b->date;

        //Since the income date is formatted like this d/m/Y , we have to change it
        $date1 = date_format(date_create_from_format('d/m/Y', $date1), 'Y-m-d');
        $date2 = date_format(date_create_from_format('d/m/Y', $date2), 'Y-m-d');

        if ($date1 > $date2) {
            return -1;
        }
        if ($date1 == $date2) {
            return 0;
        }
        if ($date1 < $date2) {
            return 1;
        }
    });
    $dataFinal->status_custom = $array_custom_object; //Result

Answer 7

use DateTime for sorting date :

$a = array(
    new DateTime('2016-01-02'),
    new DateTime('2016-05-01'),
    new DateTime('2015-01-01'),
    new DateTime('2016-01-01')
);
asort($a);
var_dump($a);

The output would be :

array(4) {
  [2]=>
  object(DateTime)#3 (3) {
    ["date"]=>
    string(26) "2015-01-01 00:00:00.000000"
    ["timezone_type"]=>
    int(3)
    ["timezone"]=>
    string(10) "US/Pacific"
  }
  [3]=>
  object(DateTime)#4 (3) {
    ["date"]=>
    string(26) "2016-01-01 00:00:00.000000"
    ["timezone_type"]=>
    int(3)
    ["timezone"]=>
    string(10) "US/Pacific"
  }
  [0]=>
  object(DateTime)#1 (3) {
    ["date"]=>
    string(26) "2016-01-02 00:00:00.000000"
    ["timezone_type"]=>
    int(3)
    ["timezone"]=>
    string(10) "US/Pacific"
  }
  [1]=>
  object(DateTime)#2 (3) {
    ["date"]=>
    string(26) "2016-05-01 00:00:00.000000"
    ["timezone_type"]=>
    int(3)
    ["timezone"]=>
    string(10) "US/Pacific"
  }
}

Answer 8

You definitely can sort array to timestamps with the given code below, but I would like to drag your attention to the format of time I have used to store.. There are different benefits of storing time in such format. Read more about this here https://stackoverflow.com/a/59912185/7997043

function compareByTimeStamp($a, $b ) {
    return strtotime($b) - strtotime($a);
}
$arr = array("2020-02-11 00:00:00", "2020-02-13 00:00:00", "2020-02-08 00:00:00"); 
usort($arr, "compareByTimeStamp"); 
echo json_encode($arr);