array_walk(3) [php man page]

ARRAY_WALK(3)								 1							     ARRAY_WALK(3)

array_walk - Apply a user supplied function to every member of an array

SYNOPSIS

       bool array_walk NULL (array  &$array, callable  $callback, [mixed  $userdata])

DESCRIPTION

	Applies the user-defined $callback function to each element of the $array array.

       array_walk(3)  is  not  affected  by  the  internal array pointer of $array. array_walk(3) will walk through the entire array regardless of
       pointer position.

PARAMETERS

	      o $array
		- The input array.

	      o $callback
		- Typically, $callback takes on two parameters. The $array parameter's value being the first, and the key/index second.

	      Note

		      If $callback needs to be working with the actual values of the array, specify the first parameter of $callback as  a  refer-
		     ence. Then, any changes made to those elements will be made in the original array itself.

	      Note

		      Many  internal  functions  (for example strtolower(3)) will throw a warning if more than the expected number of argument are
		     passed in and are not usable directly as a $callback.

	       Only the values of the $array may potentially be changed; its structure cannot be altered, i.e., the programmer cannot  add,  unset
	      or  reorder  elements.  If  the  callback  does not respect this requirement, the behavior of this function is undefined, and unpre-
	      dictable.

	      o $userdata
		- If the optional $userdata parameter is supplied, it will be passed as the third parameter to the $callback.

RETURN VALUES

	Returns TRUE on success or FALSE on failure.

ERRORS
/EXCEPTIONS
	If function $callback requires more parameters than given to it, an error of level  E_WARNING will be generated  each  time  array_walk(3)
       calls $callback.

EXAMPLES

       Example #1

	      array_walk(3) example

	      <?php
	      $fruits = array("d" => "lemon", "a" => "orange", "b" => "banana", "c" => "apple");

	      function test_alter(&$item1, $key, $prefix)
	      {
		  $item1 = "$prefix: $item1";
	      }

	      function test_print($item2, $key)
	      {
		  echo "$key. $item2<br />
";
	      }

	      echo "Before ...:
";
	      array_walk($fruits, 'test_print');

	      array_walk($fruits, 'test_alter', 'fruit');
	      echo "... and after:
";

	      array_walk($fruits, 'test_print');
	      ?>

	      The above example will output:

	      Before ...:
	      d. lemon
	      a. orange
	      b. banana
	      c. apple
	      d. fruit: lemon
	      a. fruit: orange
	      b. fruit: banana
	      c. fruit: apple

SEE ALSO

       array_walk_recursive(3),  iterator_apply(3),  list(3), each(3), call_user_func_array(3), array_map(3), information about the callback type,
       foreach.

PHP Documentation Group 													     ARRAY_WALK(3)

ARRAY(3)								 1								  ARRAY(3)

array - Create an array

SYNOPSIS

       array array ([mixed  $...])

DESCRIPTION

	Creates an array. Read the section on the array type for more information on what an array is.

PARAMETERS

	      o $...
		-  Syntax  "index  => values", separated by commas, define index and values. index may be of type string or integer. When index is
		omitted, an integer index is automatically generated, starting at 0. If index is an integer, next generated index will be the big-
		gest  integer  index  +  1. Note that when two identical index are defined, the last overwrite the first.  Having a trailing comma
		after the last defined array entry, while unusual, is a valid syntax.

RETURN VALUES

	Returns an array of the parameters. The parameters can be given an index with the => operator. Read the section on the array type for more
       information on what an array is.

EXAMPLES

	The following example demonstrates how to create a two-dimensional array, how to specify keys for associative arrays, and how to skip-and-
       continue numeric indices in normal arrays.

       Example #1

	      array(3) example

	      <?php
	      $fruits = array (
		  "fruits"  => array("a" => "orange", "b" => "banana", "c" => "apple"),
		  "numbers" => array(1, 2, 3, 4, 5, 6),
		  "holes"   => array("first", 5 => "second", "third")
	      );
	      ?>

       Example #2

	      Automatic index with array(3)

	      <?php
	      $array = array(1, 1, 1, 1,  1, 8 => 1,  4 => 1, 19, 3 => 13);
	      print_r($array);
	      ?>

	      The above example will output:

	      Array
	      (
		  [0] => 1
		  [1] => 1
		  [2] => 1
		  [3] => 13
		  [4] => 1
		  [8] => 1
		  [9] => 19
	      )

	Note that index '3' is defined twice, and keep its final value of 13. Index 4 is defined after index 8, and next  generated  index  (value
       19) is 9, since biggest index was 8.

	This example creates a 1-based array.

       Example #3

	      1-based index with array(3)

	      <?php
	      $firstquarter = array(1 => 'January', 'February', 'March');
	      print_r($firstquarter);
	      ?>

	      The above example will output:

	      Array
	      (
		  [1] => January
		  [2] => February
		  [3] => March
	      )

	As  in Perl, you can access a value from the array inside double quotes. However, with PHP you'll need to enclose your array between curly
       braces.

       Example #4

	      Accessing an array inside double quotes

	      <?php

	      $foo = array('bar' => 'baz');
	      echo "Hello {$foo['bar']}!"; // Hello baz!

	      ?>

NOTES

       Note

	      array(3) is a language construct used to represent literal arrays, and not a regular function.

SEE ALSO

       array_pad(3), list(3), count(3), range(3), foreach, The array type.

PHP Documentation Group 														  ARRAY(3)