array_intersect_assoc : intersection of two or more arrays with additional index check

array_intersect_assoc(): Intersection of two or more arrays

This function takes two or more arrays as input and then returns the associative array containing all the values in input array ( $array1) that are present in all of the arguments.

$new_array = array_intersect_assoc ($array1, $array2,....);

$array1 : Required , the input array which will be checked.
$array2 : Required , the value and key to be matched with $array1.

Here keys are also used for comparison in addition to values. ( In array_intersect() only values are used for comparison )

Example with two arrays

$first=array('One' =>1,'Two'=>2,'Three'=>3,'Four'=>'Fourth');
$second=array('One'=>1,'Two'=>2,'Third'=>3);

$result1=array_intersect_assoc($first,$second);
while (list ($key, $val) = each ($result1)) {
echo "$key -> $val <br>";
}

Output is here.

One -> 1 
Two -> 2

Keys of the first index are retained. ( no re-indexing done here) . The third element is not included as the key is different in both arrays.

Example with three arrays

$first=array('One' =>1,'Two'=>2,'Three'=>3,'Four'=>'Fourth');
$second=array('One'=>1,'Two'=>2,'Third'=>3);
$third=array('One'=>1);
$result1=array_intersect_assoc($first,$second,$third);
while (list ($key, $val) = each ($result1)) {
echo "$key -> $val <br>";
}

Output is here.

One -> 1

Example: Case-Insensitive Key Comparison

$array1 = ["A" => "apple", "b" => "banana"];
$array2 = ["a" => "apple", "B" => "banana"];
$result = array_intersect_uassoc($array1, $array2, 'strcasecmp');
print_r($result);
// Output: Array ( [A] => apple [b] => banana )

Difference between arrays considering values
Array REFERENCE

Subhendu Mohapatra

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