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

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:

Flowchart: Change the array values to upper or lower case

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

PHP: ?: operator (the 'Elvis operator') in PHP

It evaluates to the left operand if the left operand is truthy, and the right operand otherwise.

In pseudocode,

foo = bar ?: baz;

roughly resolves to

foo = bar ? bar : baz;

or

if (bar) {
    foo = bar;
} else {
    foo = baz;
}

with the difference that bar will only be evaluated once.

You can also use this to do a "self-check" of foo as demonstrated in the code example you posted:

foo = foo ?: bar;

This will assign bar to foo if foo is null or falsey, else it will leave foo unchanged.

Some more examples:

<?php
    var_dump(5 ?: 0); // 5
    var_dump(false ?: 0); // 0
    var_dump(null ?: 'foo'); // 'foo'
    var_dump(true ?: 123); // true
    var_dump('rock' ?: 'roll'); // 'rock'
?>

By the way, it's called the Elvis operator.

Ref : https://bit.ly/2SYEI83