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Introduction> <Variable and Type Related Extensions
Last updated: Fri, 10 Jul 2009

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Arrays

  • Introduction
  • Installing/Configuring
  • Predefined Constants
  • Sorting Arrays
  • Array Functions
    • array_change_key_case — Changes all keys in an array
    • array_chunk — Split an array into chunks
    • array_combine — Creates an array by using one array for keys and another for its values
    • array_count_values — Counts all the values of an array
    • array_diff_assoc — Computes the difference of arrays with additional index check
    • array_diff_key — Computes the difference of arrays using keys for comparison
    • array_diff_uassoc — Computes the difference of arrays with additional index check which is performed by a user supplied callback function
    • array_diff_ukey — Computes the difference of arrays using a callback function on the keys for comparison
    • array_diff — Computes the difference of arrays
    • array_fill_keys — Fill an array with values, specifying keys
    • array_fill — Fill an array with values
    • array_filter — Filters elements of an array using a callback function
    • array_flip — Exchanges all keys with their associated values in an array
    • array_intersect_assoc — Computes the intersection of arrays with additional index check
    • array_intersect_key — Computes the intersection of arrays using keys for comparison
    • array_intersect_uassoc — Computes the intersection of arrays with additional index check, compares indexes by a callback function
    • array_intersect_ukey — Computes the intersection of arrays using a callback function on the keys for comparison
    • array_intersect — Computes the intersection of arrays
    • array_key_exists — Checks if the given key or index exists in the array
    • array_keys — Return all the keys of an array
    • array_map — Applies the callback to the elements of the given arrays
    • array_merge_recursive — Merge two or more arrays recursively
    • array_merge — Merge one or more arrays
    • array_multisort — Sort multiple or multi-dimensional arrays
    • array_pad — Pad array to the specified length with a value
    • array_pop — Pop the element off the end of array
    • array_product — Calculate the product of values in an array
    • array_push — Push one or more elements onto the end of array
    • array_rand — Pick one or more random entries out of an array
    • array_reduce — Iteratively reduce the array to a single value using a callback function
    • array_replace_recursive — Replaces elements from passed arrays into the first array recursively
    • array_replace — Replaces elements from passed arrays into the first array
    • array_reverse — Return an array with elements in reverse order
    • array_search — Searches the array for a given value and returns the corresponding key if successful
    • array_shift — Shift an element off the beginning of array
    • array_slice — Extract a slice of the array
    • array_splice — Remove a portion of the array and replace it with something else
    • array_sum — Calculate the sum of values in an array
    • array_udiff_assoc — Computes the difference of arrays with additional index check, compares data by a callback function
    • array_udiff_uassoc — Computes the difference of arrays with additional index check, compares data and indexes by a callback function
    • array_udiff — Computes the difference of arrays by using a callback function for data comparison
    • array_uintersect_assoc — Computes the intersection of arrays with additional index check, compares data by a callback function
    • array_uintersect_uassoc — Computes the intersection of arrays with additional index check, compares data and indexes by a callback functions
    • array_uintersect — Computes the intersection of arrays, compares data by a callback function
    • array_unique — Removes duplicate values from an array
    • array_unshift — Prepend one or more elements to the beginning of an array
    • array_values — Return all the values of an array
    • array_walk_recursive — Apply a user function recursively to every member of an array
    • array_walk — Apply a user function to every member of an array
    • array — Create an array
    • arsort — Sort an array in reverse order and maintain index association
    • asort — Sort an array and maintain index association
    • compact — Create array containing variables and their values
    • count — Count all elements in an array, or properties in an object
    • current — Return the current element in an array
    • each — Return the current key and value pair from an array and advance the array cursor
    • end — Set the internal pointer of an array to its last element
    • extract — Import variables into the current symbol table from an array
    • in_array — Checks if a value exists in an array
    • key — Fetch a key from an array
    • krsort — Sort an array by key in reverse order
    • ksort — Sort an array by key
    • list — Assign variables as if they were an array
    • natcasesort — Sort an array using a case insensitive "natural order" algorithm
    • natsort — Sort an array using a "natural order" algorithm
    • next — Advance the internal array pointer of an array
    • pos — Alias of current
    • prev — Rewind the internal array pointer
    • range — Create an array containing a range of elements
    • reset — Set the internal pointer of an array to its first element
    • rsort — Sort an array in reverse order
    • shuffle — Shuffle an array
    • sizeof — Alias of count
    • sort — Sort an array
    • uasort — Sort an array with a user-defined comparison function and maintain index association
    • uksort — Sort an array by keys using a user-defined comparison function
    • usort — Sort an array by values using a user-defined comparison function


Introduction> <Variable and Type Related Extensions
Last updated: Fri, 10 Jul 2009
 
add a note add a note User Contributed Notes
Arrays
Tyler Bannister
11-Jun-2009 01:59
To delete an individual array element use the unset function

For example:

<?PHP
    $arr
= array( "A", "B", "C" );
    unset(
$arr[1] );
   
// now $arr = array( "A", "C" );
?>

Unlink is for deleting files.
Paul
21-May-2009 09:05
To delete an individual array element use the unlink function

For example:

<?PHP
    $arr
= array( "A", "B", "C" );
   
unlink( $arr[1] );
   
// now $arr = array( "A", "C" );
?>
thomasdecaux at ebuildy dot com
15-May-2009 08:14
To browse a simple array:

<?php

foreach ($myArray AS $myItem)
{

}

?>

To browse an associative array:

<?php

foreach ($myArray AS $key=>$value)
{

}

?>

http://www.ebuildy.com
macnimble at gmail dot com
27-Mar-2009 02:59
Converting a linear array (like a mysql record set) into a tree, or multi-dimensional array can be a real bugbear. Capitalizing on references in PHP, we can 'stack' an array in one pass, using one loop, like this:

<?php
# array_stack()
# Original idea from:
# http://www.ideashower.com/our_solutions/
#   create-a-parent-child-array-structure-in-one-pass/
function array_stack (&$a, $p = '@parent', $c = '@children')
{
 
$l = $t = array();
  foreach (
$a AS $key => $val):
    if (!
$val[$p]) $t[$key] =& $l[$key];
    else
$l[$val[$p]][$c][$key] =& $l[$key];
   
$l[$key] = (array)$l[$key] + $val;
  endforeach;
  return
$a = array('tree' => $t, 'leaf' => $l);
}

# Example:
$node = array();
$node[1] = array('@parent' => 0, 'title' => 'I am node 1.');
#     ^-----------------------v Link @parent value to key.
$node[2] = array('@parent' => 1, 'title' => 'I am node 2.');
$node[3] = array('@parent' => 2, 'title' => 'I am node 3.');
$node[4] = array('@parent' => 1, 'title' => 'I am node 4.');
$node[5] = array('@parent' => 4, 'title' => 'I am node 5.');

array_stack($node);

$node['leaf'][1]['title'] = 'I am node one.';
$node['leaf'][2]['title'] = 'I am node two.';
$node['leaf'][3]['title'] = 'I am node three.';
$node['leaf'][4]['title'] = 'I am node four.';
$node['leaf'][5]['title'] = 'I am node five.';

echo
'<pre>',print_r($node['tree'],TRUE),'</pre>';
?>

Note that there's no parameter checking on the array value, but this is only to keep the function size small. One could easily a quick check in there to make sure the $a parameter was in fact an array.

Hope you find it useful. Huge thanks to Nate Weiner of IdeaShower.com for providing the original function I built on.
andyd273 at gmail dot com
24-Feb-2009 09:12
A small correction to Endel Dreyer's PHP array to javascript array function. I just changed it to show keys correctly:

            function array2js($array,$show_keys)
            {
                $dimensoes = array();
                $valores = array();
              
                $total = count ($array)-1;
                $i=0;
                foreach($array as $key=>$value){
                    if (is_array($value)) {
                        $dimensoes[$i] = array2js($value,$show_keys);
                        if ($show_keys) $dimensoes[$i] = '"'.$key.'":'.$dimensoes[$i];
                    } else {
                        $dimensoes[$i] = '"'.addslashes($value).'"';
                        if ($show_keys) $dimensoes[$i] = '"'.$key.'":'.$dimensoes[$i];
                    }
                    if ($i==0) $dimensoes[$i] = '{'.$dimensoes[$i];
                    if ($i==$total) $dimensoes[$i].= '}';
                    $i++;
                }
                return implode(',',$dimensoes);
            }
Endel Dreyer
20-Jan-2009 12:16
Function to convert PHP arrays to JavaScript Array Object:
Useful in some cases.

<?php
function array2js($array,$show_keys=false)
{
   
$dimensoes = array();
   
$valores = array();
   
   
$total = count ($array)-1;
   
$i=0;
    foreach (
$array as $key => $value) {
        if (
is_array($value)) {
           
$dimensoes[$i] = array2js($value,$show_keys);
        } else {
           
$dimensoes[$i] = '"'.addslashes($value).'"';
            if (
$show_keys) '"'.$key.'":'.$dimensoes[$i];
        }
        if (
$i==0) $dimensoes[$i] = '['.$dimensoes[$i];
        if (
$i==$total) $dimensoes[$i].= ']';
       
$i++;
    }
    return
implode(',',$dimensoes);
}
?>
Anonymous
26-Nov-2008 06:36
@jorge at andrade dot cl
This variant is faster:
<?php
function array_avg($array,$precision=2){
    if(!
is_array($array))
        return
'ERROR in function array_avg(): this is a not array';

    foreach(
$array as $value)
        if(!
is_numeric($value))
            return
'ERROR in function array_avg(): the array contains one or more non-numeric values';
   
   
$cuantos=count($array);
  return
round(array_sum($array)/$cuantos,$precision);
}
?>
jorge at andrade dot cl
12-Nov-2008 08:03
To calculate the average of a array

<?php
function array_avg($array,$precision="2"){
   
$a=0;
    if(
is_array($array)){
        foreach(
$array as $value):
            if(!
is_numeric($value)){
               
$a++;
            }
        endforeach;
        if(
$a==0){
           
$cuantos=count($array);
            return
round(array_sum($array)/$cuantos,$precision);
        }else{
            return
"ERROR in function array_avg(): the array contains one or more non-numeric values";
        }       
    }else{
        return
"ERROR in function array_avg(): this is a not array";
    }
}
?>
alan dot lake at lakeinfoworks dot com
22-Oct-2008 03:46
To delete an array key (and its value) from an array:

<?php
   
function array_delete(&$ary,$key_to_be_deleted)
    {
       
$new = array();
        if(
is_string($key_to_be_deleted)) {
            if(!
array_key_exists($key_to_be_deleted,$ary)) {
                return;
            }
            foreach(
$ary as $key => $value) {
                if(
$key != $key_to_be_deleted) {
                   
$new[$key] = $value;
                }
            }
           
$ary = $new;
        }
        if(
is_array($key_to_be_deleted)) {
            foreach(
$key_to_be_deleted as $del) {
               
array_delete(&$ary,$del);
            }
        }
    }
?>
webmaster at infoproducts dot x10hosting dot com
11-Oct-2008 02:13
New value can also be added to the array as shown below.
$theVariable["google"] = "http//google.com";
or
$theVariable["1"] = "http//google.com";
Jack A
07-Oct-2008 03:14
Note that arrays are not allowed in class constants and trying to do so will throw a fatal error.
contact at greyphoenix dot biz
01-Jul-2008 04:36
<?php
//Creating a multidimensional array

$theVariable = array("Search Engines" =>
array (
   
0=> "http//google.com",
   
1=> "http//yahoo.com",
   
2=> "http//msn.com/"),

"Social Networking Sites" =>
array (
   
0 => "http//www.facebook.com",
   
1 => "http//www.myspace.com",
   
2 => "http//vkontakte.ru",)
);

echo
"The first array value is " . $theVariable['Search Engines'][0];
?>

-- Output--
The first array value is http://google.com
applegrew at rediffmail dot com
28-May-2008 03:23
For newbies like me.

Creating new arrays:-
//Creates a blank array.
$theVariable = array();

//Creates an array with elements.
$theVariable = array("A", "B", "C");

//Creating Associaive array.
$theVariable = array(1 => "http//google.com", 2=> "http://yahoo.com");

//Creating Associaive array with named keys
$theVariable = array("google" => "http//google.com", "yahoo"=> "http://yahoo.com");

Note:
New value can be added to the array as shown below.
$theVariable[] = "D";
$theVariable[] = "E";

Introduction> <Variable and Type Related Extensions
Last updated: Fri, 10 Jul 2009
 
 
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