array_replace

    (PHP 5 >= 5.3.0, PHP 7, PHP 8)

    array_replace — Replaces elements from passed arrays into the first array

    Description

    array_replace(array $array, array ...$replacements): array

    array_replace() replaces the values of array with values having the same keys in each of the following arrays. If a key from the first array exists in the second array, its value will be replaced by the value from the second array. If the key exists in the second array, and not the first, it will be created in the first array. If a key only exists in the first array, it will be left as is. If several arrays are passed for replacement, they will be processed in order, the later arrays overwriting the previous values.

    array_replace() is not recursive : it will replace values in the first array by whatever type is in the second array.

    Parameters

    array

    The array in which elements are replaced.

    replacements

    Arrays from which elements will be extracted. Values from later arrays overwrite the previous values.

    Return Values

    Returns an array.

    Examples

    Example #1 array_replace() example

    <?php
    $base     = array("orange", "banana", "apple", "raspberry");
    $replacements = array(0 => "pineapple", 4 => "cherry");
    $replacements2 = array(0 => "grape");

    $basket = array_replace($base, $replacements, $replacements2);
    print_r($basket);
    ?>

    The above example will output:

    Array
(
    [0] => grape
    [1] => banana
    [2] => apple
    [3] => raspberry
    [4] => cherry
)

    See Also

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    User Contributed Notes 14 notes

    up
    28
    steelpandrummer
    12 years ago
    <?php
    // we wanted the output of only selected array_keys from a big array from a csv-table
    // with different order of keys, with optional suppressing of empty or unused values

    $values = array
    (
    'Article'=>'24497',
    'Type'=>'LED',
    'Socket'=>'E27',
    'Dimmable'=>'',
    'Wattage'=>'10W'
    );

    $keys = array_fill_keys(array('Article','Wattage','Dimmable','Type','Foobar'), ''); // wanted array with empty value

    $allkeys = array_replace($keys, array_intersect_key($values, $keys)); // replace only the wanted keys

    $notempty = array_filter($allkeys, 'strlen'); // strlen used as the callback-function with 0==false

    print '<pre>';
    print_r($allkeys);
    print_r($notempty);

    /*
    Array
    (
    [Article] => 24497
    [Wattage] => 10W
    [Dimmable] =>
    [Type] => LED
    [Foobar] =>
    )
    Array
    (
    [Article] => 24497
    [Wattage] => 10W
    [Type] => LED
    )
    */
    ?>
    up
    7
    marvin_elia at web dot de
    10 years ago
    Simple function to replace array keys. Note you have to manually select wether existing keys will be overrided.

    /**
    * @param array $array
    * @param array $replacements
    * @param boolean $override
    * @return array
    */
    function array_replace_keys(array $array, array $replacements, $override = false) {
    foreach ($replacements as $old => $new) {
    if(is_int($new) || is_string($new)){
    if(array_key_exists($old, $array)){
    if(array_key_exists($new, $array) && $override === false){
    continue;
    }
    $array[$new] = $array[$old];
    unset($array[$old]);
    }
    }
    }
    return $array;
    }
    up
    3
    mail at romansklenar dot cz
    14 years ago
    To get exactly same result like in PHP 5.3, the foreach loop in your code should look like:

    <?php
    ...
    $count = func_num_args();

    for (    $i = 1; $i < $count; $i++) {
    ...
    }
    ...
    ?>

    Check on this code:

    <?php
    $base     = array('id' => NULL, 'login' => NULL, 'credit' => NULL);
    $arr1 = array('id' => 2, 'login' => NULL, 'credit' => 5);
    $arr2 = array('id' => NULL, 'login' => 'john.doe', 'credit' => 100);
    $result = array_replace($base, $arr1, $arr2);

    /*
    correct output:

    array(3) {
    "id" => NULL
    "login" => string(8) "john.doe"
    "credit" => int(100)
    }

    your output:

    array(3) {
    "id" => int(2)
    "login" => NULL
    "credit" => int(5)
    }
    */
    ?>

    Function array_replace "replaces elements from passed arrays into the first array" -- this means replace from top-right to first, then from top-right - 1 to first, etc, etc...
    up
    3
    ali dot sweden19 at yahoo dot com
    8 years ago
    Here is a simple array_replace_keys function:

    /**
    * This function replaces the keys of an associate array by those supplied in the keys array
    *
    * @param $array target associative array in which the keys are intended to be replaced
    * @param $keys associate array where search key => replace by key, for replacing respective keys
    * @return array with replaced keys
    */
    private function array_replace_keys($array, $keys)
    {
    foreach ($keys as $search => $replace) {
    if ( isset($array[$search])) {
    $array[$replace] = $array[$search];
    unset($array[$search]);
    }
    }

    return $array;
    }

    // Test Drive

    print_r(array_replace_keys(['one'=>'apple', 'two'=>'orange'], ['one'=>'ett', 'two'=>'tvo']);
    // Output
    array(
    'ett'=>'apple',
    'tvo'=>'orange'
    )
    up
    3
    sun at drupal dot org
    13 years ago
    Instead of calling this function, it's often faster and simpler to do this instead:

    <?php
    $array_replaced     = $array2 + $array1;
    ?>

    If you need references to stay intact:

    <?php
    $array2     += $array1;
    ?>
    up
    2
    polecat at p0lecat dot com
    13 years ago
    I got hit with a noob mistake. :)

    When the function was called more than once, it threw a function redeclare error of course. The enviroment I was coding in never called it more than once but I caught it in testing and here is the fully working revision. A simple logical step was all that was needed.

    With PHP 5.3 still unstable for Debian Lenny at this time and not knowing if array_replace would work with multi-dimensional arrays, I wrote my own. Since this site has helped me so much, I felt the need to return the favor. :)

    <?php
    // Polecat's Multi-dimensional array_replace function
    // Will take all data in second array and apply to first array leaving any non-corresponding values untouched and intact
    function polecat_array_replace( array &$array1, array &$array2 ) {
    // This sub function is the iterator that will loop back on itself ad infinitum till it runs out of array dimensions
    if(!function_exists('tier_parse')){
    function     tier_parse(array &$t_array1, array&$t_array2) {
    foreach (    $t_array2 as $k2 => $v2) {
    if (    is_array($t_array2[$k2])) {
    tier_parse($t_array1[$k2], $t_array2[$k2]);
    } else {
    $t_array1[$k2] = $t_array2[$k2];
    }
    }
    return     $t_array1;
    }
    }

    foreach (    $array2 as $key => $val) {
    if (    is_array($array2[$key])) {
    tier_parse($array1[$key], $array2[$key]);
    } else {
    $array1[$key] = $array2[$key];
    }
    }
    return     $array1;
    }
    ?>

    [I would also like to note] that if you want to add a single dimensional array to a multi, all you must do is pass the matching internal array key from the multi as the initial argument as such:

    <?php
    $array1     = array( "berries" => array( "strawberry" => array( "color" => "red", "food" => "desserts"), "dewberry" = array( "color" => "dark violet", "food" => "pies"), );

    $array2 = array( "food" => "wine");

    $array1["berries"]["dewberry"] = polecat_array_replace($array1["berries"]["dewberry"], $array2);
    ?>

    This is will replace the value for "food" for "dewberry" with "wine".

    The function will also do the reverse and add a multi to a single dimensional array or even a 2 tier array to a 5 tier as long as the heirarchy tree is identical.

    I hope this helps atleast one person for all that I've gained from this site.
    up
    2
    gmastro77 at gmail dot com
    11 years ago
    In some cases you might have a structured array from the database and one
    of its nodes goes like this;

    <?php
    # a random node structure
    $arr = array(
    'name' => 'some name',
    'key2' => 'value2',
    'title' => 'some title',
    'key4' => 4,
    'json' => '[1,0,1,1,0]'
    );

    # capture these keys values into given order
    $keys = array( 'name', 'json', 'title' );
    ?>

    Now consider that you want to capture $arr values from $keys.
    Assuming that you have a limitation to display the content into given keys
    order, i.e. use it with a vsprintf, you could use the following

    <?php
    # string to transform
    $string = "<p>name: %s, json: %s, title: %s</p>";

    # flip keys once, we will use this twice
    $keys = array_flip( $keys );

    # get values from $arr
    $test = array_intersect_key( $arr, $keys );

    # still not good enough
    echo vsprintf( $string, $test );
    // output --> name: some name, json: some title, title: [1,0,1,1,0]

    # usage of array_replace to get exact order and save the day
    $test = array_replace( $keys, $test );

    # exact output
    echo vsprintf( $string, $test );
    // output --> name: some name, json: [1,0,1,1,0], title: some title

    ?>

    I hope that this will save someone's time.
    up
    1
    kyberprizrak
    10 years ago
    if(!function_exists('array_replace'))
    {
    function array_replace()
    {
    $args = func_get_args();
    $num_args = func_num_args();
    $res = array();
    for($i=0; $i<$num_args; $i++)
    {
    if(is_array($args[$i]))
    {
    foreach($args[$i] as $key => $val)
    {
    $res[$key] = $val;
    }
    }
    else
    {
    trigger_error(__FUNCTION__ .'(): Argument #'.($i+1).' is not an array', E_USER_WARNING);
    return NULL;
    }
    }
    return $res;
    }
    }
    up
    0
    vlk dot charles at gmail dot com
    4 months ago
    I think it is worth mentioning that the array passed as the first argument is not modified and is left intact. A new array is returned. I think the wording of this documentation could be improved because it suggests that the passed array *is* modified.

    If you want to modify your existing array, it is not enough to do:

    array_replace($arrayToModify, $arrayWithModifications);

    You have to assign the returned value back to it like so:

    $arrayToModify = array_replace($arrayToModify, $arrayWithModifications);
    up
    0
    lm713
    9 years ago
    If the arrays are associative (that is, their keys are strings), then I believe this function is identical to (the older) array_merge.
    up
    -2
    ricardophp yahoocombr
    2 years ago
    Concerning the affirmation:
    If you want to append array elements from the second array to the first array while not overwriting the elements from the first array and not re-indexing, use the + array union operator

    Clearing the fact (it means ...):
    If the first array have a key and a value it will not be overlap by the new array. therefore if you have an array like [1=>"alpha", 2=>"beta"] and you got a new array telling [1=>"Alpha", 3=>"Gamma"] the final array will be [1=>"alpha", 2=>"beta", 3=>"Gamma"]. The values of first array will not be modified in the result array.

    So, if you are building a concatenation array where the values sometimes overlaps each other keys and you must preserve values you better use array_merge instead "plus" sign
    up
    -1
    projacore at gmail dot com
    9 years ago
    You can also use:

    <?php
    $myarray     = [
    "Orange",
    "572" => "Banana",
    "omg" => "Chili",
    "nevermind" => "mango"
    ];

    $myarray[0] = "NO-Orange";
    $myarray["572"] = "BANANAPHONE!!!";
    $myarray["omg"] = "NO-Chili";

    print_r($myarray);

    ?>

    RESULT:
    Array
    (
    [0] => NO-Orange
    [572] => BANANAPHONE!!!
    [omg] => NO-Chili
    [nevermind] => mango
    )

    with regards
    up
    -1
    polecat at p0lecat dot com
    13 years ago
    I would like to add to my previous note about my polecat_array_replace function that if you want to add a single dimensional array to a multi, all you must do is pass the matching internal array key from the multi as the initial argument as such:

    $array1 = array( "berries" => array( "strawberry" => array( "color" => "red", "food" => "desserts"), "dewberry" = array( "color" => "dark violet", "food" => "pies"), );

    $array2 = array( "food" => "wine");

    $array1["berries"]["dewberry"] = polecat_array_replace($array1["berries"]["dewberry"], $array2);

    This is will replace the value for "food" for "dewberry" with "wine".

    The function will also do the reverse and add a multi to a single dimensional array or even a 2 tier array to a 5 tier as long as the heirarchy tree is identical.

    I hope this helps atleast one person for all that I've gained from this site.
    up
    -2
    Anonymous
    9 years ago
    The documentation is wrongly phrased: "array_replace() replaces the values of array1" No replacing is done. A new array is created which looks like the one that would have resulted from the described replacement.

    If you want to augment the set of indices in an array, use
    array_to_be_modified += array_with_indices_to_add;
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