PHP Array Exercises : Lower-case and upper-case, all elements in an array

Last update on May 30 2025 13:14:45 (UTC/GMT +8 hours)

36. Convert Array Elements to Lower and Upper Case

Write a PHP script to lower-case and upper-case, all elements in an array.

Sample Solution:

PHP Code:

<?php
// Define an array with string values
$colors = array( "Red", "Green", "Black", "White"); 

// Display the original array using print_r
print_r($colors);

// Use array_map and strtolower to create an array with lowercase versions of each string
$lower_colors = array_map('strtolower', $colors);

// Display the array containing lowercase versions
print_r($lower_colors);

// Use array_map and strtoupper to create an array with uppercase versions of each string
$upper_colors = array_map('strtoupper', $colors);

// Display the array containing uppercase versions
print_r($upper_colors);

?>

Output:

Array                                                       
(                                                           
    [0] => Red                                              
    [1] => Green                                            
    [2] => Black                                            
    [3] => White                                            
)                                                           
Array                                                       
(                                                           
    [0] => red                                              
    [1] => green                                            
    [2] => black                                            
    [3] => white                                            
)                                                           
Array                                                       
(                                                           
    [0] => RED                                              
    [1] => GREEN                                            
    [2] => BLACK                                            
    [3] => WHITE                                            
)

Flowchart:

For more Practice: Solve these Related Problems:

Write a PHP script to convert all array elements to lowercase using array_map() and display the modified array.
Write a PHP function to convert array elements to uppercase and then merge the original and converted arrays into a single result.
Write a PHP program to toggle the case of each element in an array and output both versions side by side.
Write a PHP script to use array_walk() to change the case of each array element based on a parameter indicating 'upper' or 'lower'.

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PHP Code Editor:

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