array_diff_uassoc(): Difference between two arrays considering additional key checks through callback function

$new_array = array_diff_uassoc ($array1, $array2,....,my_function());

Example with two arrays

function my_function($a, $b)
{
    if ($a === $b) {
        return 0;
    }
    return ($a > $b)? 1:-1;
}

$first=array('One' =>'First','Two'=>'Second','Three'=>'Third','Fourth');
$second=array('One'=> 'First','Fourth','2nd');

$result=array_diff_uassoc($first,$second,"my_function");
while (list ($key, $val) = each ($result)) {
echo "$key -> $val <br>";
}

Two -> Second 
Three -> Third 

Example 1: Basic Usage of array_diff_uassoc()

This example compares two associative arrays based on both keys and values using a custom function for key comparison.

$array1 = ['a' => 'apple', 'b' => 'banana', 'c' => 'cherry'];
$array2 = ['a' => 'apple', 'B' => 'banana', 'd' => 'date'];

function custom_compare($key1, $key2) {
    return strcmp($key1, $key2); // Case-sensitive comparison
}

$result = array_diff_uassoc($array1, $array2, 'custom_compare');
print_r($result);

Array
(
    [b] => banana
    [c] => cherry
)

Example 2: Discarding Items Conditionally

This example demonstrates removing items from the first array that have the same key and value as in the second array, with case-insensitive comparison.

$array1 = ['A' => 'apple', 'b' => 'banana', 'C' => 'cherry'];
$array2 = ['a' => 'apple', 'B' => 'banana', 'd' => 'date'];

function case_insensitive_compare($key1, $key2) {
    return strcasecmp($key1, $key2); // Case-insensitive comparison
}

$result = array_diff_uassoc($array1, $array2, 'case_insensitive_compare');
print_r($result);

Array
(
    [C] => cherry
)

$array1 = ['A' => 'apple', 'b' => 'banana', 'C' => 'cherry'];
$array2 = ['a' => 'apple', 'B' => 'banana', 'd' => 'date'];

function case_insensitive_compare($key1, $key2) {
    return strcmp($key1, $key2); // Case-insensitive comparison
}

$result = array_diff_uassoc($array1, $array2, 'case_insensitive_compare');
print_r($result);

Array ( [A] => apple [b] => banana [C] => cherry )

Subhendu Mohapatra

Author & Instructor at plus2net

I write and maintain practical tutorials on Python, PHP, SQL, JavaScript, HTML, jQuery, and web development at plus2net. The tutorials focus on clear explanations, working examples, and code that readers can test and adapt while learning.

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