Sort a multidimensional array by date element in PHP (original) (raw)

Last Updated : 07 Jan, 2020

Sorting a multidimensional array by element containing date. Use the usort() function to sort the array. The usort() function is PHP builtin function that sorts a given array using user-defined comparison function. This function assigns new integral keys starting from zero to array elements.Syntax:

boolean usort( $array, "function_name")

Parameters: This function accepts two parameters as shown in the above syntax and are described below:

$array: This parameter specifies the array which u want to sort.
function_name: This parameter specifies the name of a user-defined function which compares the values and sort the array specified by the parameter $array. This function returns an integer value based on the following conditions. If two argument are equal then it returns 0, If first argument is greater than second, it returns 1 and if first argument is smaller than second, it returns -1.

Return Value: This function returns Boolean type value. It returns TRUE in case of success and FALSE in case of failure. We use strtotime to convert given time string to a timestamp object. Once we have timestamps, we subtract them to decide greater.Program:

php `

"GFG_1", "datetime" => "2019-02-22 11:29:45", ), Array ( "gfg" => "GFG_2", "datetime" => "2019-02-13 11:29:45", ), Array ( "gfg" => "GFG_3", "datetime" => "2019-02-15 11:29:45", ) ); // Comparison function function date_compare($element1, $element2) { datetime1=strtotime(datetime1 = strtotime(datetime1=strtotime(element1['datetime']); datetime2=strtotime(datetime2 = strtotime(datetime2=strtotime(element2['datetime']); return datetime1−datetime1 - datetime1−datetime2; } // Sort the array usort($array, 'date_compare'); // Print the array print_r($array) ?>

Output:

Array ( [0] => Array ( [gfg] => GFG_2 [datetime] => 2019-02-13 11:29:45 )

[1] => Array
    (
        [gfg] => GFG_3
        [datetime] => 2019-02-15 11:29:45
    )

[2] => Array
    (
        [gfg] => GFG_1
        [datetime] => 2019-02-22 11:29:45
    )

)