PHP 7.0.6 Released

    array_change_key_case

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

    array_change_key_case — Changes the case of all keys in an array

    Description

    array array_change_key_case ( array $array [, int $case = CASE_LOWER ] )

    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, or FALSE if array is not an array.

    Errors/Exceptions

    Throws E_WARNING if array is not an array.

    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.

    User Contributed Notes

    qeremy [atta] gmail [dotta] com
    4 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
    )
    Lus Henrique Pessoa
    5 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"
      }
    }
    andreas dot schuhmacher87 at googlemail dot com
    8 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;
        }
    ?>
    xsaero00
    2 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));
    }
    JOE
    4 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);

    ?>
    Luis Henrique Pessoa
    5 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"
      }
    }
    oulala at yandex dot com
    2 months 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 $res;
        }
    }
    john at doe dot com
    8 years ago
    <?php
    function array_change_value_case($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;
    }
    ?>
    cm at gameswelt dot de
    8 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
    )
    */
    NetPanther
    3 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 )
    charles
    7 years ago
    <?php
    $input_array     = array("FirSt" => 1, "SecOnd" => 4);
    print_r(array_change_key_case($input_array, CASE_UPPER));
    ?>
    aidan at php dot net
    11 years ago
    This functionality is now implemented in the PEAR package PHP_Compat.

    More information about using this function without upgrading your version of PHP can be found on the below link:

    http://pear.php.net/package/PHP_Compat
    anon at ymous dot com
    7 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;
        }
    ?>
    info at microweb dot lt
    6 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;   
    }
    ?>
    dot dot dot dot dot alexander at gmail dot com
    8 years ago
    Basically this is the function if your version is lower than 4.2.0
    <?php
    if ( !defined('CASE_LOWER') )define('CASE_LOWER', 0);
    if ( !    defined('CASE_UPPER') )define('CASE_UPPER', 1);

    if(!    function_exists("array_change_key_case")){
        function     array_change_key_case($input, $case=0){
            if(!    is_array($input))return FALSE;
                $product = array();
            foreach(    $input as $key => $value){
                if(    $case){ //Upper
                        $key2 = (  (is_string($key)) ? (strtoupper($key)) : ($key)  );
                        $product[$key2] = $value;
                }
                else{     //Lower
                        $key2 = (  (is_string($key)) ? (strtolower($key)) : ($key)  );
                        $product[$key2] = $value;
                }
            }
            return     $product;
        }    /* endfunction array_change_key_case */
    }/* endfunction exists array_change_key_case*/
    ?>
    david at ramaboo dot com
    7 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;
        }
    }
    ?>
    To Top