array_intersect_assoc

    (PHP 4 >= 4.3.0, PHP 5, PHP 7, PHP 8)

    array_intersect_assoc — Computes the intersection of arrays with additional index check

    Description

    array_intersect_assoc(array $array, array ...$arrays): array

    array_intersect_assoc() returns an array containing all the values of array that are present in all the arguments. Note that the keys are also used in the comparison unlike in array_intersect().

    Parameters

    array

    The array with master values to check.

    arrays

    Arrays to compare values against.

    Return Values

    Returns an associative array containing all the values in array that are present in all of the arguments.

    Changelog

    Version Description
    8.0.0 This function can now be called with only one parameter. Formerly, at least two parameters have been required.

    Examples

    Example #1 array_intersect_assoc() example

    <?php
    $array1     = array("a" => "green", "b" => "brown", "c" => "blue", "red");
    $array2 = array("a" => "green", "b" => "yellow", "blue", "red");
    $result_array = array_intersect_assoc($array1, $array2);
    print_r($result_array);
    ?>

    The above example will output:

    Array
(
    [a] => green
)

    In our example you see that only the pair "a" => "green" is present in both arrays and thus is returned. The value "red" is not returned because in $array1 its key is 0 while the key of "red" in $array2 is 1, and the key "b" is not returned because its values are different in each array.

    The two values from the key => value pairs are considered equal only if (string) $elem1 === (string) $elem2 . In other words a strict type check is executed so the string representation must be the same.

    See Also

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    User Contributed Notes 2 notes

    up
    6
    Whitend
    12 years ago
    One of the ways to get intersection of two arrays is as follows:

    <?php
    function arrayIntersect( $primary_array, $secondary_array ) {

    if ( !    is_array( $primary_array ) || !is_array( $secondary_array ) ) {
    return     false;
    }

    if ( !empty(     $primary_array ) ) {

    foreach(     $primary_array as $key => $value ) {

    if ( !isset(     $secondary_array[$key] ) ) {
    unset(     $primary_array[$key] );
    } else {
    if (     serialize( $secondary_array[$key] ) != serialize( $value ) ) {
    unset(     $primary_array[$key] );
    }
    }

    }

    return     $primary_array;

    } else {
    return array();
    }

    }
    ?>

    It would pay attention to both keys and values even if values would be arrays as well. One important note is that if value of $primary_array is yet another array, its order of key & value pairs becomes important for matching.
    up
    4
    vandor at progressive dot hu
    19 years ago
    # ket tomb kulcs alapu metszetet szamitja ki, az erteken is ellenorzest vegez
    #
    # calculating (key base) intersection of arrays (value are checked)
    # use: $result_array = array_intersect_assoc($a1, $a2, $a3,..);
    #
    ##
    # original code by [jochem at iamjochem dawt com] : array_diff_keys()

    <?php
    function array_intersect_assoc() {

    $args = func_get_args();
    $res = $args[0];

    for (    $i=1;$i<count($args);$i++) {
    if (!    is_array($args[$i])) {continue;}

    foreach (    $res as $key => $data) {
    if ( (!    array_key_exists($key, $args[$i])) || ( (isset($args[$i][$key])) && ($args[$i][$key] !== $res[$key]) ) ) {
    unset(    $res[$key]);
    }
    }
    }

    return     $res;
    }

    ?>

    <?php
    $array1     = array("a"=>"green", "b"=>"brown", "c"=>"blue", "red");
    $array2 = array("a"=>"green", "b"=>"yellow", "c"=>"yellow", "red");
    $a = array('a'=>'green', 'b'=>'brown', 'c'=>'yellow');
    $b = array('a'=>'green', 'b'=>'brown', 'c'=>'yellow', 'e'=>'yellow');

    $result_array = array_intersect_assoc($a, $b, $array1, $array2);
    ?>

    $args array will look like:

    (
    0 =>
    (
    a => green
    b => brown
    c => yellow
    )

    1 =>
    (
    a => green
    b => brown
    c => yellow
    e => yellow
    )

    2 =>
    (
    a => green
    b => brown
    c => blue
    0 => red
    )

    3 =>
    (
    a => green
    b => yellow
    c => yellow
    0 => red
    )

    )

    $result_array will look like:

    (
    a => green
    )
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