PHP Array Exercises : Change the array values to upper or lower case

Last update on May 30 2022 11:49:59 (UTC/GMT +8 hours)

PHP Array: Exercise-12 with Solution

Write a PHP function to change the following array's all values to upper or lower case.

Sample arrays :
$Color = array('A' => 'Blue', 'B' => 'Green', 'c' => 'Red');

Sample Solution:

PHP Code:

<?php
function array_change_value_case($input, $ucase)
{
$case = $ucase;
$narray = array();
if (!is_array($input))
{
return $narray;
}
foreach ($input as $key => $value)
{
if (is_array($value))
{
$narray[$key] = array_change_value_case($value, $case);
 continue;
}
$narray[$key] = ($case == CASE_UPPER ? strtoupper($value) : strtolower($value));
}
return $narray;
}
$Color = array('A' => 'Blue', 'B' => 'Green', 'c' => 'Red');
echo 'Actual array 
';
print_r($Color);
echo '
Values are in lower case.
';
$myColor = array_change_value_case($Color,CASE_LOWER);
print_r($myColor);
echo '
Values are in upper case.
';
$myColor = array_change_value_case($Color,CASE_UPPER);
print_r($myColor);
?>

Sample Output:

Actual array Array                                          
(                                                           
    [A] => Blue                                             
    [B] => Green                                            
    [c] => Red                                              
)                                                           
Values are in lower case.Array                              
(                                                           
    [A] => blue                                             
    [B] => green                                            
    [c] => red                                              
)                                                           
Values are in upper case.Array                              
(                                                           
    [A] => BLUE                                             
    [B] => GREEN                                            
    [c] => RED                                              
)

Flowchart:

PHP Code Editor:

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Previous: Write a PHP program to merge (by index) the specified two arrays.
Next: Write a PHP script which displays all the numbers between 200 and 250 that are divisible by 4.

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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