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array_change_key_case

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

array_change_key_case — 将数组中的所有键名修改为全大写或小写

说明

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

array_change_key_case() 将 array 数组中的所有键名改为全小写或大写。本函数不改变数字索引。

参数

array: 需要操作的数组。
case: 可以在这里用两个常量，CASE_UPPER 或 CASE_LOWER（默认值）。

返回值

返回一个键全是小写或者全是大写的数组；

示例

示例 #1 array_change_key_case()例一

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

以上示例会输出：

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

注释

注意:
如果一个数组中的多个键名经过本函数后变成一样的话（例如 "keY" 和 "kEY"），最后一个值将覆盖其它的值。

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User Contributed Notes 20 notes

down

qeremy [atta] gmail [dotta] com ¶

11 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
)

down

zhangxuejiang ¶

4 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));
}

down

wendri dot net at gmail dot com ¶

1 year 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
        )

)

down

xsaero00 ¶

9 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));
}

down

msegit post pl ¶

2 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
        )
)

down

andreas dot schuhmacher87 at googlemail dot com ¶

15 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;
    }
?>

down

shaman_master at list dot ru ¶

4 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)
    );
}
?>

down

-1

gsoft ¶

3 months 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;
}

down

-3

anon at ymous dot com ¶

14 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;

    }

?>

down

-3

NetPanther ¶

11 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 )

down

-5

Lus Henrique Pessoa ¶

13 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"
  }
}

down

-5

Luis Henrique Pessoa ¶

13 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"
  }
}

down

-5

john at doe dot com ¶

16 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;
}
?>

down

-6

JOE ¶

12 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);

?>

down

-4

cm at gameswelt dot de ¶

16 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
)
*/

down

-5

oulala at yandex dot com ¶

7 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;
    }
}

down

-7

ahmadz ¶

7 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
 )

down

-10

info at microweb dot lt ¶

13 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;    

}

?>

down

-14

david at ramaboo dot com ¶

14 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;

    }

}

?>

down

-21

charles ¶

14 years ago

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

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