rfc:array_column

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rfc:array_column [2012/06/21 19:19] – created ramseyrfc:array_column [2013/01/11 23:58] – ramsey
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 ====== Request for Comments: array_column ====== ====== Request for Comments: array_column ======
  
-  * Version: 1.0 +  * Version: 2.1 
-  * Date: 2012-06-21+  * Date: 2013-01-11
   * Author: Ben Ramsey <ramsey@php.net>   * Author: Ben Ramsey <ramsey@php.net>
   * Status: Under Discussion   * Status: Under Discussion
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 This RFC proposes a new array function that returns the values of the specified column from a multi-dimensional array. Inspired by database methods like ''PDOStatement::fetchColumn()'', ''array_column()'' moves useful functionality into the core that once had to be implemented in userland code with sometimes complex loops. This RFC proposes a new array function that returns the values of the specified column from a multi-dimensional array. Inspired by database methods like ''PDOStatement::fetchColumn()'', ''array_column()'' moves useful functionality into the core that once had to be implemented in userland code with sometimes complex loops.
  
-This has been submitted as a [[https://github.com/php/php-src/pull/56|pull request on GitHub]], where there has already been a significant amount of discussion.+This has been submitted as a [[https://github.com/php/php-src/pull/257|pull request on GitHub]], where there has already been a significant amount of discussion.
  
 ===== Specification ===== ===== Specification =====
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 ==== Description ==== ==== Description ====
  
-  array array_column(array $input, mixed $key)+  array array_column(array $input, mixed $columnKey[, mixed $indexKey]) 
 +  array array_pluck(array $input, mixed $columnKey[, mixed $indexKey])
  
-''array_column()'' returns the values from a single column of the //**input**// array, identified by the //**key**//.+''array_column()'' returns the values from a single column of the //**input**// array, identified by the //**columnKey**//. Optionally, you may provide an //**indexKey**// to index the values in the returned array by the values from the //**indexKey**// column in the //**input**// array. 
 + 
 +''array_pluck()'' is an alias of ''array_column()''.
  
 ==== Parameters ==== ==== Parameters ====
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 > A multi-dimensional array (record set) from which to pull a column of values. > A multi-dimensional array (record set) from which to pull a column of values.
  
-**key**+**columnKey**
  
 > The column of values to return. This value may be the 0-indexed number of the column you wish to retrieve, or it may be the string key name for an associative array. > The column of values to return. This value may be the 0-indexed number of the column you wish to retrieve, or it may be the string key name for an associative array.
 +
 +**indexKey**
 +
 +> (Optional.) The column to use as the index/keys for the returned array. This value may be the 0-indexed number of the column, or it may be the string key name.
  
 ==== Return Values ==== ==== Return Values ====
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 $records = array( $records = array(
     array(     array(
-        'id' => 1,+        'id' => 2135,
         'first_name' => 'John',         'first_name' => 'John',
         'last_name' => 'Doe'         'last_name' => 'Doe'
     ),     ),
     array(     array(
-        'id' => 2,+        'id' => 3245,
         'first_name' => 'Sally',         'first_name' => 'Sally',
         'last_name' => 'Smith'         'last_name' => 'Smith'
     ),     ),
     array(     array(
-        'id' => 3,+        'id' => 5342,
         'first_name' => 'Jane',         'first_name' => 'Jane',
         'last_name' => 'Jones'         'last_name' => 'Jones'
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 ); );
  
-$firstNames = array_column($records, 2); +$lastNames = array_column($records, 2); 
-print_r($firstNames);+print_r($lastNames);
 </code> </code>
  
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     [1] => Smith     [1] => Smith
     [2] => Jones     [2] => Jones
 +)
 +</code>
 +
 +=== Example #3: Get column of last names from recordset, indexed by the "id" column ===
 +
 +<code php>
 +<?php
 +// Array representing a possible record set returned from a database
 +$records = array(
 +    array(
 +        'id' => 2135,
 +        'first_name' => 'John',
 +        'last_name' => 'Doe'
 +    ),
 +    array(
 +        'id' => 3245,
 +        'first_name' => 'Sally',
 +        'last_name' => 'Smith'
 +    ),
 +    array(
 +        'id' => 5342,
 +        'first_name' => 'Jane',
 +        'last_name' => 'Jones'
 +    )
 +);
 +
 +$lastNames = array_column($records, 'last_name', 'id');
 +print_r($lastNames);
 +</code>
 +
 +The above example will output:
 +
 +<code>
 +Array
 +(
 +    [2135] => Doe
 +    [3245] => Smith
 +    [5342] => Jones
 ) )
 </code> </code>
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 ===== Proposal and Patch ===== ===== Proposal and Patch =====
  
-The patch (including tests) for this proposal is available in [[https://github.com/php/php-src/pull/56|GitHub Pull Request #56]].+The patch (including tests) for this proposal is available in [[https://github.com/php/php-src/pull/257|GitHub Pull Request #257]].
  
 ===== Changelog ===== ===== Changelog =====
  
   * 1.0 (2012-06-21): Initial draft, following discussion on on [[https://github.com/php/php-src/pull/56|GitHub Pull Request #56]]   * 1.0 (2012-06-21): Initial draft, following discussion on on [[https://github.com/php/php-src/pull/56|GitHub Pull Request #56]]
- +  * 2.0 (2013-01-11): Updated to reflect mailing list and pull request feedback. 
 +  * 2.1 (2013-01-11): Adding link to new pull request: https://github.com/php/php-src/pull/257
rfc/array_column.txt · Last modified: 2017/09/22 13:28 by 127.0.0.1

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