PHP Array Exercises : Sorted array without preserving the keys

Last update on May 30 2022 11:45:21 (UTC/GMT +8 hours)

PHP Array: Exercise-40 with Solution

Write a PHP program to get a sorted array without preserving the keys.

Sample Solution:

PHP Code:

<?php
$my_array = array("red", "black", "green", "black", "white", "yellow"); 

$sorted_unique_array = array_values(array_unique($my_array)); 

print_r($sorted_unique_array);
?>

Sample Output:

Array                                                       
(                                                           
    [0] => Red                                              
    [1] => Green                                            
    [2] => White                                            
    [3] => Black                                            
)                                                           
Array                                                       
(                                                           
    [0] => 100                                              
    [1] => 200                                              
    [2] => -10                                              
    [3] => 0                                                
)

Flowchart:

PHP Code Editor:

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Previous: Write a PHP program to remove duplicate values from an array which contains only strings or only integers.
Next: Write a PHP program to identify the email addresses which are not unique.

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PHP: Tips of the Day

How to Sort Multi-dimensional Array by Value?

Try a usort, If you are still on PHP 5.2 or earlier, you'll have to define a sorting function first:

Example:

function sortByOrder($a, $b) {
    return $a['order'] - $b['order'];
}

usort($myArray, 'sortByOrder');

Starting in PHP 5.3, you can use an anonymous function:

usort($myArray, function($a, $b) {
    return $a['order'] - $b['order'];
});

And finally with PHP 7 you can use the spaceship operator:

usort($myArray, function($a, $b) {
    return $a['order'] <=> $b['order'];
});

To extend this to multi-dimensional sorting, reference the second/third sorting elements if the first is zero - best explained below. You can also use this for sorting on sub-elements.

usort($myArray, function($a, $b) {
    $retval = $a['order'] <=> $b['order'];
    if ($retval == 0) {
        $retval = $a['suborder'] <=> $b['suborder'];
        if ($retval == 0) {
            $retval = $a['details']['subsuborder'] <=> $b['details']['subsuborder'];
        }
    }
    return $retval;
});

If you need to retain key associations, use uasort() - see comparison of array sorting functions in the manual

Ref : https://bit.ly/3i77vCC