array_change_key_case

    (PHP 4 >= 4.2.0, PHP 5, PHP 7, PHP 8)

    array_change_key_case — Changes the case of all keys in an array

    Description

    array_change_key_case(array $array, int $case = CASE_LOWER): array

    Returns an array with all keys from array lowercased or uppercased. Numbered indices are left as is.

    Parameters

    array

    The array to work on

    case

    Either CASE_UPPER or CASE_LOWER (default)

    Return Values

    Returns an array with its keys lower or uppercased.

    Examples

    Example #1 array_change_key_case() example

    <?php
    $input_array     = array("FirSt" => 1, "SecOnd" => 4);
    print_r(array_change_key_case($input_array, CASE_UPPER));
    ?>

    The above example will output:

    Array
(
    [FIRST] => 1
    [SECOND] => 4
)

    Notes

    Note:

    If an array has indices that will be the same once run through this function (e.g. "keY" and "kEY"), the value that is later in the array will override other indices.

    Improve This Page

    Learn How To Improve This Page • Submit a Pull Request • Report a Bug
    ＋add a note

    User Contributed Notes 12 notes

    up
    27
    qeremy [atta] gmail [dotta] com
    12 years ago
    Unicode example;

    <?php
    function array_change_key_case_unicode($arr, $c = CASE_LOWER) {
    $c = ($c == CASE_LOWER) ? MB_CASE_LOWER : MB_CASE_UPPER;
    foreach (    $arr as $k => $v) {
    $ret[mb_convert_case($k, $c, "UTF-8")] = $v;
    }
    return     $ret;
    }

    $arr = array("FirSt" => 1, "yağ" => "Oil", "şekER" => "sugar");
    print_r(array_change_key_case($arr, CASE_UPPER));
    print_r(array_change_key_case_unicode($arr, CASE_UPPER));
    ?>

    Array
    (
    [FIRST] => 1
    [YAğ] => Oil
    [şEKER] => sugar
    )
    Array
    (
    [FIRST] => 1
    [YAĞ] => Oil
    [ŞEKER] => sugar
    )
    up
    12
    xsaero00
    10 years ago
    Here is the most compact way to lower case keys in a multidimensional array

    function array_change_key_case_recursive($arr)
    {
    return array_map(function($item){
    if(is_array($item))
    $item = array_change_key_case_recursive($item);
    return $item;
    },array_change_key_case($arr));
    }
    up
    8
    zhangxuejiang
    5 years ago
    I improve the array_change_key_case_recursive function ,let it can lowercase or uppercase keys

    function array_change_key_case_recursive($arr, $case = CASE_LOWER)
    {
    return array_map(function($item) use($case) {
    if(is_array($item))
    $item = array_change_key_case_recursive($item, $case);
    return $item;
    },array_change_key_case($arr, $case));
    }
    up
    2
    msegit post pl
    3 years ago
    Improved multidimensional unicode func (after qeremy):
    <?php
    function array_change_key_case_unicode_recurs($arr, $c = CASE_LOWER) {
    foreach (    $arr as $k => $v) {
    $ret[mb_convert_case($k, (($c === CASE_LOWER) ? MB_CASE_LOWER : MB_CASE_UPPER), "UTF-8")] = (is_array($v) ? array_change_key_case_unicode_recurs($v, $c) : $v );
    }
    return     $ret;
    }

    $arr = array("FirSt" => 1, "ZażóŁć gęŚlą jaŹń" => array("yağ" => "Oil", "şekER" => "sugar") );
    print_r(array_change_key_case($arr, CASE_UPPER));
    print_r(array_change_key_case_unicode_recurs($arr, CASE_UPPER));
    ?>

    Array
    (
    [FIRST] => 1
    [ZAżóŁć GęŚLą JAŹń] => Array
    (
    [yağ] => Oil
    [şekER] => sugar
    )
    )
    Array
    (
    [FIRST] => 1
    [ZAŻÓŁĆ GĘŚLĄ JAŹŃ] => Array
    (
    [YAĞ] => Oil
    [ŞEKER] => sugar
    )
    )
    up
    -2
    gsoft
    1 year ago
    //Array key case change recursively (Unicode):

    <?php
    function array_key_case($data,$case=FALSE)
    {
    $ret=array();
    if (     is_array($data) )
    foreach (    $data as $idx => $val)
    $ret[$case ? mb_strtoupper($idx) : mb_strtolower($idx)]=array_key_case($val,$case);
    else
    $ret=$data;
    return     $ret;
    }
    up
    0
    andreas dot schuhmacher87 at googlemail dot com
    16 years ago
    multibyte and multi-dimensional-array support, have fun!

    <?php
    define    ('ARRAY_KEY_FC_LOWERCASE', 25); //FOO => fOO
    define('ARRAY_KEY_FC_UPPERCASE', 20); //foo => Foo
    define('ARRAY_KEY_UPPERCASE', 15); //foo => FOO
    define('ARRAY_KEY_LOWERCASE', 10); //FOO => foo
    define('ARRAY_KEY_USE_MULTIBYTE', true); //use mutlibyte functions

    /**
    * change the case of array-keys
    *
    * use: array_change_key_case_ext(array('foo' => 1, 'bar' => 2), ARRAY_KEY_UPPERCASE);
    * result: array('FOO' => 1, 'BAR' => 2)
    *
    * @param array
    * @param int
    * @return array
    */
    function array_change_key_case_ext(array $array, $case = 10, $useMB = false, $mbEnc = 'UTF-8') {
    $newArray = array();

    //for more speed define the runtime created functions in the global namespace

    //get function
    if($useMB === false) {
    $function = 'strToUpper'; //default
    switch($case) {
    //first-char-to-lowercase
    case 25:
    //maybee lcfirst is not callable
    if(!function_exists('lcfirst'))
    $function = create_function('$input', '
    return strToLower($input[0]) . substr($input, 1, (strLen($input) - 1));
    '    );
    else     $function = 'lcfirst';
    break;

    //first-char-to-uppercase
    case 20:
    $function = 'ucfirst';
    break;

    //lowercase
    case 10:
    $function = 'strToLower';
    }
    } else {
    //create functions for multibyte support
    switch($case) {
    //first-char-to-lowercase
    case 25:
    $function = create_function('$input', '
    return mb_strToLower(mb_substr($input, 0, 1, \''     . $mbEnc . '\')) .
    mb_substr($input, 1, (mb_strlen($input, \''     . $mbEnc . '\') - 1), \'' . $mbEnc . '\');
    '    );

    break;

    //first-char-to-uppercase
    case 20:
    $function = create_function('$input', '
    return mb_strToUpper(mb_substr($input, 0, 1, \''     . $mbEnc . '\')) .
    mb_substr($input, 1, (mb_strlen($input, \''     . $mbEnc . '\') - 1), \'' . $mbEnc . '\');
    '    );

    break;

    //uppercase
    case 15:
    $function = create_function('$input', '
    return mb_strToUpper($input, \''     . $mbEnc . '\');
    '    );
    break;

    //lowercase
    default: //case 10:
    $function = create_function('$input', '
    return mb_strToLower($input, \''     . $mbEnc . '\');
    '    );
    }
    }

    //loop array
    foreach($array as $key => $value) {
    if(    is_array($value)) //$value is an array, handle keys too
    $newArray[$function($key)] = array_change_key_case_ex($value, $case, $useMB);
    elseif(    is_string($key))
    $newArray[$function($key)] = $value;
    else     $newArray[$key] = $value; //$key is not a string
    } //end loop

    return $newArray;
    }
    ?>
    up
    -1
    shaman_master at list dot ru
    5 years ago
    <?php
    /**
    * Convert keys in an array.
    *
    * @param array $array Source data
    * @param callable $callback Function name (strtolower, strtoupper, ucfirst, lcfirst, ucwords)
    * @return array
    */
    function array_convert_key_case(array $array, callable $callback = 'strtolower')
    {
    return     array_combine(
    array_map($callback, array_keys($array)),
    array_values($array)
    );
    }
    ?>
    up
    -2
    NetPanther
    12 years ago
    Use this to capitalize first letter of all array keys:

    <?php

    function ucfirstKeys(&$data)
    {
    foreach (    $data as $key => $value)
    {
    // Convert key
    $newKey = ucfirst($key);

    // Change key if needed
    if ($newKey != $key)
    {
    unset(    $data[$key]);
    $data[$newKey] = $value;
    }

    // Handle nested arrays
    if (is_array($value))
    {
    ucfirstKeys($data[$key]);
    }
    }
    }

    $test = array('foo' => 'bar', 'moreFoo' => array('more' => 'foo'));
    ucfirstKeys($test);
    print_r($test);

    ?>

    Result:
    Array ( [MoreFoo] => Array ( [More] => foo ) [Foo] => bar )
    up
    -3
    anon at ymous dot com
    15 years ago
    Below is a recursive version of this function.

    <?php
    /**
    * A recursive array_change_key_case function.
    * @param array $input
    * @param integer $case
    */
    function array_change_key_case_recursive($input, $case = null){
    if(!    is_array($input)){
    trigger_error("Invalid input array '{$array}'",E_USER_NOTICE); exit;
    }
    // CASE_UPPER|CASE_LOWER
    if(null === $case){
    $case = CASE_LOWER;
    }
    if(!    in_array($case, array(CASE_UPPER, CASE_LOWER))){
    trigger_error("Case parameter '{$case}' is invalid.", E_USER_NOTICE); exit;
    }
    $input = array_change_key_case($input, $case);
    foreach(    $input as $key=>$array){
    if(    is_array($array)){
    $input[$key] = array_change_key_case_recursive($array, $case);
    }
    }
    return     $input;
    }
    ?>
    up
    -3
    cm at gameswelt dot de
    17 years ago
    I just changed the code a little bit so you havent got a code that repeats itself.

    <?php

    function array_change_key_case_secure($array = array(), $case = CASE_UPPER){
    $secure = array();
    $functionWrap = array(CASE_UPPER => 'strtoupper',
    CASE_LOWER => 'strtolower');

    foreach(    $array as $key => $val){
    if(isset(    $functionWrap[$key])){
    $key = $functionWrap[$case]($key);
    $secure[$key][] = $val;
    } else {
    die(    'Not a known Type');
    }
    }

    foreach(    $secure as $key => $val){
    if(    count($secure[$key]) == 1){
    $secure[$key] = $val[0];
    }
    }

    return     $secure;
    }

    $myArray = array('A' => 'Hello',
    'B' => 'World',
    'a' => 'how are you?');

    print_r($myArray);
    $myArray = array_change_key_case_secure($myArray);
    print_r($myArray);

    /*
    Array
    (
    [A] => Hello
    [B] => World
    [a] => how are you?
    )
    Array
    (
    [A] => Array
    (
    [0] => Hello
    [1] => how are you?
    )

    [B] => World
    )
    */
    up
    -5
    john at doe dot com
    17 years ago
    <?php
    function array_change_value_case($input, $case = CASE_LOWER)
    {
    $aRet = array();

    if (!    is_array($input))
    {
    return     $aRet;
    }

    foreach (    $input as $key => $value)
    {
    if (    is_array($value))
    {
    $aRet[$key] = array_change_value_case($value, $case);
    continue;
    }

    $aRet[$key] = ($case == CASE_UPPER ? strtoupper($value) : strtolower($value));
    }

    return     $aRet;
    }
    ?>
    up
    -2
    wendri dot net at gmail dot com
    2 years ago
    Array of partitions with always the same number of sub-array indexes.

    <?php

    function partitionFixedSubArray($array, $length, $empty_space)
    {
    $result = [];

    if (     sizeof($array) ) {

    $result = array_chunk($array, $length);
    $last_array_count = sizeof(end($result));

    if (    $last_array_count < $length) {

    for (    $i = $last_array_count; $i < $length; $i++) {
    array_push($result[key($result)], $empty_space);
    }
    }
    }

    return     $result;
    }

    $employees = [
    "Paidi",
    "Paijo",
    "Darno",
    "Kusnan",
    "Mukidi",
    "Sarno",
    "Nurdin",
    "Parmen",
    "Sukinah",
    "Sartini",
    "Sukijan",
    "Yono",
    "Supoyo"
    ];

    echo     "<pre>";
    print_r(partitionFixedSubArray($employees, 5, "empty space"));
    echo     "</pre>";

    ?>

    Output:
    Array
    (
    [0] => Array
    (
    [0] => Paidi
    [1] => Paijo
    [2] => Darno
    [3] => Kusnan
    [4] => Mukidi
    )

    [1] => Array
    (
    [0] => Sarno
    [1] => Nurdin
    [2] => Parmen
    [3] => Sukinah
    [4] => Sartini
    )

    [2] => Array
    (
    [0] => Sukijan
    [1] => Yono
    [2] => Supoyo
    [3] => empty space
    [4] => empty space
    )

    )
    ＋add a note
    To Top