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

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