array_combine

说明

array array_combine ( array keys, array values )

返回一个 array，用来自 keys 数组的值作为键名，来自 values 数组的值作为相应的值。

如果两个数组的单元数不同或者数组为空时返回 FALSE。

例子 1. 简单的 array_combine() 例子
<?php $a = array('green', 'red', 'yellow'); $b = array('avocado', 'apple', 'banana'); $c = array_combine($a, $b); print_r($c); ?>
上例将输出：
Array ( [green] => avocado [red] => apple [yellow] => banana )

参见 array_merge()，array_walk() 和 array_values()。

add a note User Contributed Notes

MSpreij, c/o GMail
10-Sep-2006 04:47


And another one..

<?php

if (! function_exists('array_combine')) {

  function array_combine($keys, $values) {

    foreach($keys as $key) $out[$key] = array_shift($values);

    return $out;

  }

}

?>



If there are less values then keys, the extra values will be NULL (that's what array_shift returns).

glashio.at.gmail.com
07-Dec-2005 06:00


I encounterd a "Fatal Error" on PHP4 while i developed on PHP5 using : array_combine($a, $b);



__TOP_OF_SCRIPT__



if (!function_exists('array_combine')) {

    function array_combine($a, $b) {

        $c = array();

        if (is_array($a) && is_array($b))

            while (list(, $va) = each($a))

                if (list(, $vb) = each($b))

                    $c[$va] = $vb;

                else

                    break 1;

        return $c;

    }

}

m at momech dot dk
01-Nov-2005 11:55


An 3-liner way to get the effect of array_combine in PHP4:

<?php

$keysValues = array();

foreach($csvFieldnames as $indexnum => $key)

    $keyValues[$key] = $values[$indexnum];

?>



/ Mogens

Ivo van Sandick
02-Sep-2005 04:04


Such a useful function, and only since version 5! Why an emulation for earlier PHP versions has not been posted long ago, is a mystery:



<?php

function array_combine_emulated( $keys, $vals ) {

 $keys = array_values( (array) $keys );

 $vals = array_values( (array) $vals );

 $n = max( count( $keys ), count( $vals ) );

 $r = array();

 for( $i=0; $i<$n; $i++ ) {

  $r[ $keys[ $i ] ] = $vals[ $i ];

 }

 return $r;

}

?>

ifeghali at interveritas dot net
27-Feb-2005 02:53


Use that code to group an array by its first element.



<?



function groupbyfirst($array)

{

    foreach ($array as $row)

    {

        $firstkey = array_keys($row);

        $firstkey = $firstkey[0];

        $key = $row[$firstkey];

        unset($row[$firstkey]);

        $newarray[$key][] = $row;

    }

    return $newarray;

}



?>



Example:



<?



$array = 

Array(

    0 => Array('color' => 'red','name' => 'apple', 'quantity' => '3'),

    1 => Array('color' => 'green','name' => 'pear', 'quantity' => '2'),

    2 => Array('color' => 'yellow','name' => 'corn', 'quantity' => '3'),

    3 => Array('color' => 'blue','name' => 'grape', 'quantity' => '4'),

    4 => Array('color' => 'yellow','name' => 'banana', 'quantity' => '13'),

);



$output = groupbyfirst($array);

print_r($output);



?>



will return:



Array

(

 [red] => Array ( [0] => Array ( [name] => apple [quantity] => 3 ) )

 [green] => Array ( [0] => Array ( [name] => pear [quantity] => 2 ) )

 [yellow] => Array ( [0] => Array ( [name] => corn [quantity] => 3 ), [1] => Array ( [name] => banana [quantity] => 13 ) )

 [blue] => Array ( [0] => Array ( [name] => grape [quantity] => 4 ))

)



Or you can use mysql recordset:



<?

while ($row=mysql_fetch_array($result,MYSQL_ASSOC))

{

    $firstkey = array_keys($row);

    $firstkey = $firstkey[0];

    $key = $row[$firstkey];

    unset($row[$firstkey]);

    $newarray[$key][] = $row;

}

?>

aidan at php dot net
21-May-2004 10:15


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

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