Edit Report a Bug

    array_change_key_case

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

    array_change_key_case — Ändert die Groß- oder Kleinschreibung aller Schlüssel in einem Array

    Beschreibung

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

    Gibt ein Array zurück, in dem alle Schlüssel aus array in Klein- oder Großbuchstaben umgewandelt wurden. Numerische Indizes werden nicht geändert.

    Parameter-Liste

    array

    Das Eingabe-Array

    case

    Entweder CASE_UPPER oder CASE_LOWER (Standard)

    Rückgabewerte

    Gibt ein Array zurück, dessen Schlüssel in Klein- oder Großbuchstaben umgewandelt wurden.

    Beispiele

    Beispiel #1 array_change_key_case()-Beispiel

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

    Das oben gezeigte Beispiel erzeugt folgende Ausgabe:

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

    Anmerkungen

    Hinweis:

    Hat ein Array Indizes, die durch die Anwendung dieser Funktion gleich werden (z. B. "keY" und "kEY"), wird der Wert des vorherigen übereinstimmenden Indexes mit dem Wert des späteren überschrieben.

    add a note add a note

    User Contributed Notes 20 notes

    up
    25
    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
    10
    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
    1
    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
            )

    )
    up
    10
    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
    1
    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
    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
    0
    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
    -1
    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
    -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
    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
    -5
    Lus Henrique Pessoa
    14 years ago
    <?php

    // improving the previous script
    function ack_r3(&$array, $case=CASE_LOWER, $flag_rec=false)
        {
              $array = array_change_key_case($array, $case);
          if (     $flag_rec ) {
            foreach (    $array as $key => $value) {
                if (     is_array($value) ) {
                        ack_r3($array[$key], $case, true);
                }
            }
          }
        }

    // same of array_change_key_case
    $arr = array('ID' => 1, 'NAME'=> 'Luis', 'Contact' => array('PHONE' => '3010-7148', 'E-MAIL' => 'luis@net.com') );
            ack_r3($arr, CASE_LOWER,false);
            var_dump($arr);
       
            $arr = array('ID' => 1, 'NAME'=> 'Luis', 'Contact' => array('PHONE' => '3010-7148', 'E-MAIL' => 'luis@net.com') );
            ack_r3($arr, CASE_LOWER,true);
            var_dump($arr);

    ?>

    outputs:

    array(3) {
      ["id"]=>
      int(1)
      ["name"]=>
      string(4) "Luis"
      ["contact"]=>
      array(2) {
        ["PHONE"]=>
        string(9) "3010-7148"
        ["E-MAIL"]=>
        string(12) "luis@net.com"
      }
    }
    array(3) {
      ["id"]=>
      int(1)
      ["name"]=>
      string(4) "Luis"
      ["contact"]=>
      array(2) {
        ["phone"]=>
        string(9) "3010-7148"
        ["e-mail"]=>
        string(12) "luis@net.com"
      }
    }
    up
    -5
    Luis Henrique Pessoa
    14 years ago
    Script to change case of sub-arrays keys:

    <?php

            function arrKey2Lower(&$arrVals) {
            foreach(     $arrVals as $key => $item ) {
                    $key2 = strtolower($key);
                if (     $key2 != $key) {
                    unset(    $arrVals[$key]);
                        $arrVals[$key2]=$item;
                        $key=$key2;
                }
               
                if (     is_array($item) ) { arrKey2Lower($arrValores[$key]); }
            }
        }
       
            $arr = array('ID' => 1, 'NAME'=> 'Luis', 'Contact' => array('PHONE' => '3010-7148', 'E-MAIL' => 'luis@net.com') );
            arrKey2Lower($arr);
            var_dump($arr);
       
       
    ?>

    outputs:

    array(3) {
      ["id"]=>
      int(1)
      ["name"]=>
      string(4) "Luis"
      ["contact"]=>
      array(2) {
        ["phone"]=>
        string(9) "3010-7148"
        ["e-mail"]=>
        string(12) "luis@net.com"
      }
    }
    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
    -6
    JOE
    13 years ago
    Script to change case of sub-arrays keys to lower . It works well for me. hope it helps.

    <?php
    $array    =array("First"=>"val1","SecoNd"=>"val2",
    "third"=>array("third-INner1"=>"val3.1"),
    "fourth"=>array("FouthINNer1"=>"val4.1","FourthINNER2"=>"val4.2"));
    print_r($array);
    $key=array_keys($array);
    foreach(    $key as $ki)
    {
            $klower=strtolower($ki);
            $val=$array[$ki];
        if(    is_array($val))
        {
            foreach(    $val as $kinner=>$vinner)
            {
               
                    $tl=strtolower($kinner);
                unset(    $val[$kinner]);
                    $val[$tl]=$vinner;
            }
        }
        unset(    $array[$ki]);
            $array[$klower]=$val;
    }
    echo     "<br> After Changing Key to-LowerCase : <br>";
    print_r($array);

    ?>
    up
    -4
    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
    oulala at yandex dot com
    8 years ago
    Recursive LowerCase First Letter in array key

    if(!function_exists("mb_lcfirstKeys")) {
        function mb_lcfirstKeys($data) {
            $res = [];
            foreach ($data as $key => $value) {
                $newKey = mb_lcfirst($key);
                $res[$newKey] = is_array($value) ? mb_lcfirstKeys($value) : $value;
            }
            return $res;
        }
    }
    up
    -7
    ahmadz
    8 years ago
    function convert_to_key_case($data, $case){

            $condition = ($case == 'lowercase')? 'lowercase' : 'uppercase';
            $test = [];
            foreach($data as  $key => $value) {
                if ($condition == 'lowercase') {
                    $test[strtolower($key)] = $value;
                } else {
                    $test[strtoupper($key)] = $value;
                }
            }
        return $test;
    }

    $input = ['test1'=>1, 'Test2' => 2, 'TeSt3' => 3];

    print_r(convert_to_key_case($input, 'uppercase'));
    print_r(convert_to_key_case($input, 'lowercase'));

    OUTPUT

    Array
    (
    [TEST1] => 1
    [TEST2] => 2
    [TEST3] => 3
    )

    Array (
    [test1] => 1
    [test2] => 2
    [test3] => 3
    )
    up
    -10
    info at microweb dot lt
    14 years ago
    Simple function to change multidimensional array's all values to uppercase. If you would like to change to lowercase then change "mb_strtoupper" to  "mb_strtolower". It works perfect for me ;)

    <?php
    function change_case_recursive($arr){
        foreach (    $arr as $key=>$val){
            if (!    is_array($arr[$key])){
                    $arr[$key]=mb_strtoupper($arr[$key]);
            }else{
                    $arr[$key]=change_case_recursive($arr[$key]);
            }
        }
        return     $arr;   
    }
    ?>
    up
    -14
    david at ramaboo dot com
    15 years ago
    Same as array_change_key_case only with the values. This should really be part of PHP!

    <?php
    /**
    * @brief Returns an array with all values lowercased or uppercased.
    * @return array Returns an array with all values lowercased or uppercased.
    * @param object $input The array to work on
    * @param int $case [optional] Either \c CASE_UPPER or \c CASE_LOWER (default).
    */
    function array_change_value_case(array $input, $case = CASE_LOWER) {
        switch (    $case) {
            case     CASE_LOWER:
                return     array_map('strtolower', $input);
                break;
            case     CASE_UPPER:
                return     array_map('strtoupper', $input);
                break;
            default:
                    trigger_error('Case is not valid, CASE_LOWER or CASE_UPPER only', E_USER_ERROR);
                return     false;
        }
    }
    ?>
    up
    -21
    charles
    15 years ago
    <?php
    $input_array     = array("FirSt" => 1, "SecOnd" => 4);
    print_r(array_change_key_case($input_array, CASE_UPPER));
    ?>
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