array_combine

add a note User Contributed Notes

Fred
09-Aug-2007 10:49


I read many workaround functions for users with php < 5

Here is mine (the simpliest I think) :



<?php

function array_combine($keys, $values) {

    $result = array() ;

    while( ($k=each($keys)) && ($v=each($values)) ) $result[$k[1]] = $v[1] ;

    return $result ;

}

?>

royanee at yahoo dot com
06-Aug-2007 05:11


This correctly accounts for the error conditions, and actually works. The previous note appears to set all the values in the result array to the value of the last item in the values input array.

<?php

function array_combine( $keys, $values )

{

   if( !is_array($keys) || !is_array($values) || empty($keys) || empty($values) || count($keys) != count($values) )

   {

      trigger_error( "array_combine() expects parameters 1 and 2 to be non-empty arrays with an equal number of elements", E_USER_WARNING );

      return false;

   }

   $keys = array_values($keys);

   $values = array_values($values);

   $result = array();

   foreach( $keys as $index => $key )

   {

      $result[$key] = $values[$index];

   }

   return $result;

}

?>

robertark at gmail dot com
02-Aug-2007 11:43


All of those 'array_combine' emulators did -not- work for me, so I created one of my own, out randomly, and it worked for me, maybe you can give it a shot and let me know how it works. Thanks..



function array_combine($arr1, $arr2)

{

  $buffer = array();

  foreach($arr1 as $key1 => $arr_1)

  {

    foreach($arr2 as $key2 => $arr_2)

      $buffer[$arr_1] = $arr_2;

  }

  return $buffer;

}

muppis
21-Jun-2007 12:46


I found these workarounds for PHP 4.4.x non-working with $_POST and $_GET arrays except Ivo van Sandick's one. Works well, even my client ISP denies to update to 4.4.7 at least..

toth dot janas at gmail dot com
01-Jun-2007 09:21


Under this note i send yesterday a function that in array show once the dupicated elements. Sorry, the function is wrong. I corrected the error and i write a new function is working right. 

/tested/.



The test array is:



$test = array(

    0 => 1,

    1 => 2,

    2 => 1,

    3 => 3,

    4 => 4,

    5 => 2,

    6 => 5,

    7 => 4

); 



the function:



function array_no_duplicate($array_tmb){

    $temp = array();

     foreach ($array_tmb as $value){

     $if_one = 0;

         foreach ($temp as $new_value) {

            if($new_value == $value)  $if_one = 1;

          }

     if($if_one == 0)  array_push($temp, $value);     

    }

    return $temp;

}



example: 

var_dump(array_no_duplicate($test));



this output will show array without duplicated elements.



Good work!

toth dot janas at gmail dot com
31-May-2007 07:48


If you have an array and include duplicated element, and you want to that this element just show once in array, then this function is very good solution. 



function array_no_duplicate($array_tmb){

    $new_array = array();

    for($i = 0; $i < count($array_tmb); $i++){

    $van = 0;

        for($j = 0; $j < count($array_tmb); $j++){

         if( $new_array[$j] == $array_tmb[$j]) $van = 1;

        }    

    if($van == 0){

         $new_array[$i] = $array_tmb[$i];

    }else continue;         

    }

    return $new_array;

}

Q1712 at online dot ms
23-Apr-2007 01:04


there was one exaple missing in my priviouse post:

<?php

print_r( array(array()), array("array()") );

?>

prints:

Array

(

    [Array] = array()

)



@admin: please merge these 2 posts

Q1712 at online dot ms
23-Apr-2007 12:56


If a value is existing twice in the $keys-array the last one overwrites the others, wich makes the returned array shorter than the given once, as usual.

If a value of the values-array is double/float, bool or array the string representaion is used, not the integer representation as usual.



<?php

print_r(

  combine(

    array('a', 'a', 'a', 0, false, 1, true, 2, 7/3),

    array("first 'a'", "second 'a'", "third 'a'", "0", "false", "1", "true", "2", "7/3")

  )

);



print_r( 

  array ('a' => "first 'a'", 'a' => "second 'a'", 'a' => "third 'a'", 0 => "0", false => "false", 1 => "1", true => "true", 2 => "2", 7/3 => "7/3")

);

?>



prints:

Array

(

    [a] => third 'a'

    [0] => 0

    [] => false

    [1] => true

    [2] => 2

    [2.33333333333] => 7/3

)

Array

(

    [a] => third 'a'

    [0] => false

    [1] => true

    [2] => 7/3

)

chriswillarddesign at yahoo dot com
10-Apr-2007 03:26


Here is my take on the combine function for PHP < 5:



<?

// Combines two associate arrays by making a array with the key being $a1 and the value $a2.

    function array_combine($a1,$a2)

    {

        for($i=0;$i<count($a1);$i++)

            $ra[$a1[$i]] = $a2[$i];

        if(isset($ra)) return $ra; else return false;

    }



?>

Wiebe
26-Mar-2007 09:05


When you have not the use off PHP 5.



The workaround off  'Ivo van Sandick' can be much shorter.

I use my function:



<?

// combine $arr with $arr_to_key where $arr_to_key becomes key of $arr.



 function array_comb($arr, $arr_to_key){



          $i = 0;

          foreach($arr_to_key AS $value){

                  $arr_combined[$value] = $arr[$i];

                  $i++;

          }



          RETURN $arr_combined;

 }



 //example.

 $arr_1[0] = 'apple';

 $arr_1[1] = 'banana';

 $arr_2[0] = 'green';

 $arr_2[1] = 'yellow';



 $arr_comb = array_comb($arr_1, $arr_2);



 //$arr_comb['green'] = 'apple'

 //$arr_comb['yellow'] = 'banana'



?>

neoyahuu at yahoo dot com
20-Mar-2007 04:36


Some tips for merging same values in an array



<?php

$array1 = array(1,2,3,4,5,6,7,8,9,10,11,12);

$array2 = array(1,2,3,13);



$merged = array_merge($array1,$array2);



// output normal array_merge

echo '<pre>After array_merge :

';

print_r($merged);

echo '</pre>';



// do double flip for merging values in an array

$merged = array_flip($merged);

$merged = array_flip($merged);



// Output after

echo '<pre>After Double Flip : 

';

print_r($merged);

echo '</pre>';

?>



Output ::



After array_merge :

Array

(

    [0] => 1

    [1] => 2

    [2] => 3

    [3] => 4

    [4] => 5

    [5] => 6

    [6] => 7

    [7] => 8

    [8] => 9

    [9] => 10

    [10] => 11

    [11] => 12

    [12] => 1

    [13] => 2

    [14] => 3

    [15] => 13

)



After Double Flip : 

Array

(

    [12] => 1

    [13] => 2

    [14] => 3

    [3] => 4

    [4] => 5

    [5] => 6

    [6] => 7

    [7] => 8

    [8] => 9

    [9] => 10

    [10] => 11

    [11] => 12

    [15] => 13

)

Ivo van Sandick
02-Sep-2005 08:04


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
26-Feb-2005 06:53


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 02:15


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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