Sorting function attributes

Function name Sorts by Maintains key association Order of sort

array_multisort() value associative yes, numeric no first array or sort options

asort() value yes low to high

arsort() value yes high to low

krsort() key yes high to low

ksort() key yes low to high

natcasesort() value yes natural, case insensitive

natsort() value yes natural

rsort() value no high to low

shuffle() value no random

sort() value no low to high

uasort() value yes user defined

uksort() key yes user defined

usort() value no user defined

• array_combine — Creates an array by using one array for keys and another for its values <?php $a1=array("a","b","c","d"); $a2=array("Cat","Dog","Horse","Cow"); print_r(array_combine($a1,$a2)); ?> Array ( [a] => Cat [b] => Dog [c] => Horse [d] => Cow )

• array_count_values — Counts all the values of an array

<?php $a=array("Cat","Dog","Horse","Dog"); print_r(array_count_values($a)); ?> Array ( [Cat] => 1 [Dog] => 2 [Horse] => 1 )

• array_merge_recursive — Merge two or more arrays recursively <?php $a1=array("a"=>"Horse","b"=>"Dog"); $a2=array("c"=>"Cow","b"=>"Cat"); print_r(array_merge_recursive($a1,$a2)); ?> The output of the code above will be: Array ( [a] => Horse [b] => Array ( [0] => Dog [1] => Cat ) [c] => Cow )

• array_merge — Merge one or more arrays <?php $a1=array("a"=>"Horse","b"=>"Dog"); $a2=array("c"=>"Cow","b"=>"Cat"); print_r(array_merge($a1,$a2)); ?>

The output of the code above will be: Array ( [a] => Horse [b] => Cat [c] => Cow )

<?php $a=array(3=>"Horse",4=>"Dog"); print_r(array_merge($a)); ?>

The output of the code above will be: Array ( [0] => Horse [1] => Dog )

• array_fill_keys — Fill an array with values, specifying keys <?php $keys = array('foo', 5, 10, 'bar'); $a = array_fill_keys($keys, 'banana');print_r($a); ?>

The above example will output: Array ( [foo] => banana [5] => banana [10] => banana [bar] => banana )

• array_fill — Fill an array with values

<?php $a = array_fill(5, 6, 'banana'); $b = array_fill(-2, 4, 'pear'); print_r($a); print_r($b); ?>

The above example will output: Array ( [5] => banana [6] => banana [7] => banana [8] => banana [9] => banana [10] => banana ) Array ( [-2] => pear [0] => pear [1] => pear [2] => pear )

• array_filter — Filters elements of an array using a callback function

<?php function myfunction($v) { if ($v==="Horse") { return true; } return false; } $a=array(0=>"Dog",1=>"Cat",2=>"Horse"); print_r(array_filter($a,"myfunction")); ?>

The output of the code above will be: Array ( [2] => Horse )

• array_flip — Exchanges all keys with their associated values in an array

<?php $a=array(0=>"Dog",1=>"Cat",2=>"Horse"); print_r(array_flip($a)); ?>

The output of the code above will be: Array ( [Dog] => 0 [Cat] => 1 [Horse] => 2 )

• array_key_exists — Checks if the given key or index exists in the array

<?php $a=array("a"=>"Dog","b"=>"Cat"); if (array_key_exists("a",$a)) { echo "Key exists!"; } else { echo "Key does not exist!"; } ?>

The output of the code above will be: Key exists!

<?php $a=array("a"=>"Dog","b"=>"Cat"); if (array_key_exists("c",$a)) { echo "Key exists!"; } else { echo "Key does not exist!"; }

?>

The output of the code above will be: Key does not exist!

<?php $a=array("Dog",Cat"); if (array_key_exists(0,$a)) { echo "Key exists!"; } else { echo "Key does not exist!"; }

?>

The output of the code above will be: Key exists!

• array_keys — Return all the keys or a subset of the keys of an array

<?php $a=array("a"=>"Horse","b"=>"Cat","c"=>"Dog"); print_r(array_keys($a)); ?>

The output of the code above will be: Array ( [0] => a [1] => b [2] => c )

<?php $a=array("a"=>"Horse","b"=>"Cat","c"=>"Dog"); print_r(array_keys($a,"Dog")); ?>

The output of the code above will be: Array ( [0] => c)

<?php $a=array(10,20,30,"10"); print_r(array_keys($a,"10",false)); ?>

The output of the code above will be: Array ( [0] => 0 [1] => 3 )

<?php $a=array(10,20,30,"10"); print_r(array_keys($a,"10",true)); ?>

The output of the code above will be: Array ( [0] => 3)

• array_map — Applies the callback to the elements of the given arrays

<?php function myfunction($v) { if ($v==="Dog") { return "Fido"; } return $v; } $a=array("Horse","Dog","Cat"); print_r(array_map("myfunction",$a)); ?>

The output of the code above will be: Array ( [0] => Horse [1] => Fido [2] => Cat )

<?php function myfunction($v1,$v2) { if ($v1===$v2) { return "same"; } return "different"; } $a1=array("Horse","Dog","Cat"); $a2=array("Cow","Dog","Rat"); print_r(array_map("myfunction",$a1,$a2)); ?>

The output of the code above will be: Array ( [0] => different [1] => same [2] => different )

<?php $a1=array("Dog","Cat"); $a2=array("Puppy","Kitten"); print_r(array_map(null,$a1,$a2)); ?>

The output of the code above will be: Array (

[0] => Array ( [0] => Dog [1] => Puppy ) [1] => Array ( [0] => Cat [1] => Kitten )

)

• array_multisort — Sort multiple or multi-dimensional arrays

<?php $a1=array("Dog","Cat"); $a2=array("Fido","Missy"); array_multisort($a1,$a2); print_r($a1); print_r($a2); ?>

The output of the code above will be: Array ( [0] => Cat [1] => Dog ) Array ( [0] => Missy [1] => Fido )

<?php $a1=array("Dog","Dog","Cat"); $a2=array("Pluto","Fido","Missy"); array_multisort($a1,$a2); print_r($a1); print_r($a2); ?>

The output of the code above will be: Array ( [0] => Cat [1] => Dog [2] => Dog ) Array ( [0] => Missy [1] => Fido [2] => Pluto )

<?php $a1=array("Dog","Dog","Cat"); $a2=array("Pluto","Fido","Missy"); array_multisort($a1,SORT_ASC,$a2,SORT_DESC); print_r($a1); print_r($a2); ?>

The output of the code above will be: Array ( [0] => Cat [1] => Dog [2] => Dog ) Array ( [0] => Missy [1] => Pluto [2] => Fido )

• array_pad — Pad array to the specified length with a value

<?php $a=array("Dog","Cat"); print_r(array_pad($a,5,0)); ?>

The output of the code above will be: Array ( [0] => Dog [1] => Cat [2] => 0 [3] => 0 [4] => 0 )

<?php $a=array("Dog","Cat"); print_r(array_pad($a,-5,0)); ?>

The output of the code above will be: Array ( [0] => 0 [1] => 0 [2] => 0 [3] => Dog [4] => Cat )

• array_pop — Pop the element off the end of array <?php

$stack = array("orange", "banana", "apple", "raspberry"); $fruit = array_pop($stack); print_r($stack);

?>

After this, $stack will have only 3 elements: Array (

[0] => orange [1] => banana [2] => apple

)

<?php $a=array("Dog","Cat","Horse"); array_pop($a); print_r($a);

?>

The output of the code above will be: Array ( [0] => Dog [1] => Cat )

• array_product — Calculate the product of values in an array

<?php $a = array(2, 4, 6, 8); echo "product(a) = " . array_product($a) . "\n"; echo "product(array()) = " . array_product(array()) . "\n"; ?>

product(a) = 384 product(array()) = 1

<?php $a=array(5,5); echo(array_product($a));

?>

25

• array_push — Push one or more elements onto the end of array

<?php $a=array("Dog","Cat"); array_push($a,"Horse","Bird"); print_r($a); ?>

The output of the code above will be: Array ( [0] => Dog [1] => Cat [2] => Horse [3] => Bird )

<?php $a=array("a"=>"Dog","b"=>"Cat"); array_push($a,"Horse","Bird"); print_r($a); ?>

The output of the code above will be: Array ( [a] => Dog [b] => Cat [0] => Horse [1] => Bird )

• array_rand — Pick one or more random entries out of an array <?php $a=array("a"=>"Dog","b"=>"Cat","c"=>"Horse"); print_r(array_rand($a,1));?>

The output of the code above could be: b

<?php $a=array("a"=>"Dog","b"=>"Cat","c"=>"Horse"); print_r(array_rand($a,2)); ?>

Array ( [0] => c [1] => b )

• array_reduce — Iteratively reduce the array to a single value using a callback function

<?php

function myfunction($v1,$v2) { return $v1 . "-" . $v2; } $a=array("Dog","Cat","Horse"); print_r(array_reduce($a,"myfunction"));

?>

The output of the code above will be: -Dog-Cat-Horse

<?php function myfunction($v1,$v2) { return $v1 . "-" . $v2; } $a=array("Dog","Cat","Horse"); print_r(array_reduce($a,"myfunction",5));

?>

The output of the code above will be: 5-Dog-Cat-Horse

<?php function myfunction($v1,$v2) { return $v1+$v2; } $a=array(10,15,20); print_r(array_reduce($a,"myfunction",5));

?>

The output of the code above will be: 50

• array_replace_recursive — Replaces elements from passed arrays into the first array recursively

<?php $base = array('citrus' => array( "orange") , 'berries' => array("blackberry", "raspberry"), ); $replacements = array('citrus' => array('pineapple'), 'berries' => array('blueberry')); $basket = array_replace_recursive($base, $replacements); print_r($basket); $basket = array_replace($base, $replacements); print_r($basket); ?>

The above example will output: Array ( [citrus] => Array ( [0] => pineapple ) [berries] => Array ( [0] => blueberry [1] => raspberry ) ) Array ( [citrus] => Array ( [0] => pineapple ) [berries] => Array ( [0] => blueberry ) )

• array_replace — Replaces elements from passed arrays into the first array <?php

$base = array("orange", "banana", "apple", "raspberry"); $replacements = array(0 => "pineapple", 4 => "cherry"); $replacements2 = array(0 => "grape"); $basket = array_replace($base, $replacements, $replacements2); print_r($basket);

?>

Array ( [0] => grape [1] => banana [2] => apple [3] => raspberry [4] => cherry )

• array_reverse — Return an array with elements in reverse order

<?php $a=array("a"=>"Dog","b"=>"Cat","c"=>"Horse"); print_r(array_reverse($a)); ?>

The output of the code above will be: Array ( [c] => Horse [b] => Cat [a] => Dog )

• array_search — Searches the array for a given value and returns the corresponding key if successful

<?php $a=array("a"=>"Dog","b"=>"Cat","c"=>"Horse"); echo array_search("Dog",$a); ?>

The output of the code above will be: a

<?php $a=array("a"=>"5","b"=>5,"c"=>"5"); echo array_search(5,$a,true); ?>

The output of the code above will be: b

• array_unique — Removes duplicate values from an array <?php

$a=array("a"=>"Cat","b"=>"Dog","c"=>"Cat"); print_r(array_unique($a));

?>

Array ( [a] => Cat [b] => Dog )

<?php $input = array("a" => "green", "red", "b" => "green", "blue", "red"); $result = array_unique($input); print_r($result);

?>

Array ( [a] => green [0] => red [1] => blue )

<?php

$input = array(4, "4", "3", 4, 3, "3"); $result = array_unique($input); var_dump($result);

?>

array(2) { [0] => int(4) [2] => string(1) "3"

}

• array_shift — Shift an element off the beginning of array <?php

$a=array("a"=>"Dog","b"=>"Cat","c"=>"Horse"); echo array_shift($a); print_r ($a);

?>

The output of the code above will be:

Dog Array ( [b] => Cat [c] => Horse )

<?php

$a=array(0=>"Dog",1=>"Cat",2=>"Horse"); echo array_shift($a); print_r ($a);

?>

The output of the code above will be:

Dog Array ( [0] => Cat [1] => Horse )

• array_unshift — Prepend one or more elements to the beginning of an array <?php $queue = array("orange", "banana"); array_unshift($queue, "apple", "raspberry"); print_r($queue); ?>

The above example will output: Array ( [0] => apple [1] => raspberry [2] => orange [3] => banana )

• array_values — Return all the values of an array <?php $a=array("a"=>"Cat","b"=>"Dog","c"=>"Horse"); print_r(array_values($a)); ?>

Array ( [0] => Cat [1] => Dog [2] => Horse )

• array_walk_recursive — Apply a user function recursively to every member of an array <?php function myfunction($value,$key) { echo "The key $key has the value $value<br />"; } $a1=array("a"=>"Cat","b"=>"Dog"); $a2=array($a1,"1"=>"Bird","2"=>"Horse"); array_walk_recursive($a2,"myfunction"); ?>

The key a has the value Cat The key b has the value Dog The key 1 has the value Bird The key 2 has the value Horse

• array_walk — Apply a user function to every member of an array

<?php function myfunction($value,$key) { echo "The key $key has the value $value<br />"; } $a=array("a"=>"Cat","b"=>"Dog","c"=>"Horse"); array_walk($a,"myfunction");

?>

The key a has the value Cat The key b has the value Dog The key c has the value Horse

<?php function myfunction($value,$key,$p) { echo "$key $p $value<br />"; } $a=array("a"=>"Cat","b"=>"Dog","c"=>"Horse"); array_walk($a,"myfunction","has the value");

?>

a has the value Cat b has the value Dog c has the value Horse

<?php function myfunction(&$value,$key) { $value="Bird"; } $a=array("a"=>"Cat","b"=>"Dog","c"=>"Horse"); array_walk($a,"myfunction"); print_r($a);

?>

Array ( [a] => Bird [b] => Bird [c] => Bird )

• array — Create an array

<?php $a=array("a"=>"Dog","b"=>"Cat","c"=>"Horse"); print_r($a); ?>

Array ( [a] => Dog [b] => Cat [c] => Horse )

<?php $a=array("Dog","Cat","Horse"); print_r($a);

?>

Array ( [0] => Dog [1] => Cat [2] => Horse )

• array_sum — Calculate the sum of values in an array <?php $a = array(2, 4, 6, 8); echo "sum(a) = " . array_sum($a) . "\n"; $b = array("a" => 1.2, "b" => 2.3, "c" => 3.4); echo "sum(b) = " . array_sum($b) . "\n"; ?>

The above example will output: sum(a) = 20 sum(b) = 6.9

• arsort — Sort an array in reverse order and maintain index association <?php $fruits = array("d" => "lemon", "a" => "orange", "b" => "banana", "c" => "apple"); arsort($fruits); foreach ($fruits as $key => $val) {

echo "$key = $val\n"; } ?>

a = orange d = lemon b = banana c = apple The fruits have been sorted in reverse alphabetical order, and the index associated with each element has been maintained.

• asort — Sort an array and maintain index association

<?php $fruits = array("d" => "lemon", "a" => "orange", "b" => "banana", "c" => "apple"); asort($fruits); foreach ($fruits as $key => $val) { echo "$key = $val\n"; } ?>

The above example will output: c = apple b = banana d = lemon a = orange The fruits have been sorted in alphabetical order, and the index associated with each element has been maintained.

• krsort — Sort an array by key in reverse order <?php $fruits = array("d"=>"lemon", "a"=>"orange", "b"=>"banana", "c"=>"apple"); krsort($fruits); foreach ($fruits as $key => $val) { echo "$key = $val\n"; } ?>

The above example will output: d = lemon c = apple b = banana a = orange

• ksort — Sort an array by key

<?php $fruits = array("d"=>"lemon", "a"=>"orange", "b"=>"banana", "c"=>"apple"); ksort($fruits); foreach ($fruits as $key => $val) { echo "$key = $val\n"; } ?>

The above example will output: a = orange b = banana c = apple d = lemon

rsort — Sort an array in reverse order <?php $fruits = array("lemon", "orange", "banana", "apple"); rsort($fruits); foreach ($fruits as $key => $val) { echo "$key = $val\n"; } ?>

The above example will output: 0 = orange 1 = lemon 2 = banana 3 = apple The fruits have been sorted in reverse alphabetical order.

• natcasesort — Sort an array using a case insensitive "natural order" algorithm

<?php $array1 = $array2 = array('IMG0.png', 'img12.png', 'img10.png', 'img2.png', 'img1.png', 'IMG3.png'); sort($array1); echo "Standard sorting\n"; print_r($array1); natcasesort($array2); echo "\nNatural order sorting (case-insensitive)\n"; print_r($array2); ?>

The above example will output: Standard sorting Array ( [0] => IMG0.png [1] => IMG3.png [2] => img1.png [3] => img10.png [4] => img12.png [5] => img2.png ) Natural order sorting (case-insensitive) Array ( [0] => IMG0.png [4] => img1.png [3] => img2.png [5] => IMG3.png [2] => img10.png [1] => img12.png )

• natsort — Sort an array using a "natural order" algorithm <?php $array1 = $array2 = array("img12.png", "img10.png", "img2.png", "img1.png"); asort($array1); echo "Standard sorting\n"; print_r($array1); natsort($array2); echo "\nNatural order sorting\n"; print_r($array2); ?>

The above example will output: Standard sorting

Array ( [3] => img1.png [1] => img10.png [0] => img12.png [2] => img2.png ) Natural order sorting Array ( [3] => img1.png [2] => img2.png [1] => img10.png [0] => img12.png )

count — Count all elements in an array, or something in an object <?php $a[0] = 1; $a[1] = 3; $a[2] = 5; $result = count($a); // $result == 3 $b[0] = 7; $b[5] = 9; $b[10] = 11; $result = count($b); // $result == 3 $result = count(null); // $result == 0 $result = count(false); // $result == 1 ?>

<?php $food = array('fruits' => array('orange', 'banana', 'apple'), 'veggie' => array('carrot', 'collard', 'pea')); echo count($food, COUNT_RECURSIVE); // output 8 echo count($food); // output 2

?>

• compact — Create array containing variables and their values

Creates an array containing variables and their values. For each of these, compact() looks for a variable with that name in the current symbol table and adds it to the output array such that the variable name becomes the key and the contents of the variable become the value for that key. In short, it does the opposite of extract(). Any strings that are not set will simply be skipped. <?php

$firstname = "Peter"; $lastname = "Griffin"; $age = "38"; $name = array("firstname", "lastname"); $result = compact($name, "location", "age"); print_r($result);

?>

Array ( [firstname] => Peter [lastname] => Griffin [age] => 38 )

• in_array — Checks if a value exists in an array

<?php $people = array("Peter", "Joe", "Glenn", "Cleveland"); if (in_array("Glenn",$people)) { echo "Match found"; } else { echo "Match not found"; } ?>

The output of the code above will be: Match found

<?php $people = array("Peter", "Joe", "Glenn", "Cleveland", 23); if (in_array("23",$people, TRUE)) { echo "Match found<br />"; }else { echo "Match not found<br />"; } if (in_array("Glenn",$people, TRUE)) { echo "Match found<br />"; }else { echo "Match not found<br />"; } if (in_array(23,$people, TRUE)) { echo "Match found<br />"; }else { echo "Match not found<br />"; } ?>

Match not found Match found Match found

• key — Fetch a key from an array <?php $people = array("Peter", "Joe", "Glenn", "Cleveland"); echo "The key from the current position is: " . key($people); ?>

The key from the current position is: 0

• list — Assign variables as if they were an array

<?php $my_array = array("Dog","Cat","Horse"); list($a, $b, $c) = $my_array; echo "I have several animals, a $a, a $b and a $c."; ?>

The output of the code above will be:

I have several animals, a Dog, a Cat and a Horse.

<?php $my_array = array("Dog","Cat","Horse"); list($a, , $c) = $my_array; echo "Here I only use the $a and $c variables."; ?>

The output of the code above will be:

Here I only use the Dog and Horse variables.

• range — Create an array containing a range of elements <?php // array(0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12) foreach (range(0, 12) as $number) { echo $number; } // The step parameter was introduced in 5.0.0 // array(0, 10, 20, 30, 40, 50, 60, 70, 80, 90, 100) foreach (range(0, 100, 10) as $number) { echo $number; } // Use of character sequences introduced in 4.1.0 // array('a', 'b', 'c', 'd', 'e', 'f', 'g', 'h', 'i'); foreach (range('a', 'i') as $letter) { echo $letter; } // array('c', 'b', 'a'); foreach (range('c', 'a') as $letter) { echo $letter; } ?>

• reset — Set the internal pointer of an array to its first element <?php $array = array('step one', 'step two', 'step three', 'step four'); echo current($array) . "<br />\n"; // "step one" next($array); next($array); echo current($array) . "<br />\n"; // "step three" reset($array); echo current($array) . "<br />\n"; // "step one" ?>

• pos — Alias of current • current — Return the current element in an array • next — Advance the internal array pointer of an array • prev — Rewind the internal array pointer

<?php $transport = array('foot', 'bike', 'car', 'plane'); $mode = current($transport); // $mode = 'foot'; $mode = next($transport); // $mode = 'bike'; $mode = current($transport); // $mode = 'bike'; $mode = prev($transport); // $mode = 'foot'; $mode = end($transport); // $mode = 'plane'; $mode = current($transport); // $mode = 'plane'; $arr = array(); var_dump(current($arr)); // bool(false) $arr = array(array()); var_dump(current($arr)); // array(0) { } ?>

• end — Set the internal pointer of an array to its last element <?php $fruits = array('apple', 'banana', 'cranberry'); echo end($fruits); ?>

// cranberry

• each — Return the current key and value pair from an array and advance the array cursor <?php $people = array("Peter", "Joe", "Glenn", "Cleveland"); print_r (each($people)); ?>

The output of the code above will be: Array ( [1] => Peter [value] => Peter [0] => 0 [key] => 0 )

<?php $people = array("Peter", "Joe", "Glenn", "Cleveland"); reset($people); while (list($key, $val) = each($people)) {

echo "$key => $val<br />"; } ?>

The output of the code above will be: 0 => Peter 1 => Joe 2 => Glenn 3 => Cleveland

• shuffle — Shuffle an array

The shuffle() function randomizes the order of the elements in the array. This function assigns new keys for the elements in the array. Existing keys will be removed. This function returns TRUE on success, or FALSE on failure. <?php $my_array = array("a" => "Dog", "b" => "Cat", "c" => "Horse");

shuffle($my_array); print_r($my_array); ?>

The output of the code above could be: Array ( [0] => Cat [1] => Horse [2] => Dog )

• sizeof — Alias of count <?php $people = array("Peter", "Joe", "Glenn", "Cleveland"); $result = sizeof($people); echo $result; ?>

• 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 • extract — Import variables into the current symbol table from an array

array_change_key_case — Changes all keys in an array Description array array_change_key_case ( array $input [, int $case = CASE_LOWER ] ) Returns an array with all keys from input lowercased or uppercased. Numbered indices are left as is. Parameters input - The array to work on case - Either CASE_UPPER or CASE_LOWER (default) Return Values

Returns an array with its keys lower or uppercased, or FALSE if input is not an array. Errors/Exceptions

Throws E_WARNING if input is not an array. Examples <?php $input_array = array("FirSt" => 1, "SecOnd" => 4); print_r(array_change_key_case($input_array, CASE_UPPER)); ?> The above example will output: Array ( [FIRST] => 1 [SECOND] => 4 )

array_chunk — Split an array into chunks Description array array_chunk ( array $input , int $size [, bool $preserve_keys = false ] ) Chunks an array into size large chunks. The last chunk may contain less than size elements. Parameters input - The array to work on size - The size of each chunk preserve_keys

When set to TRUE keys will be preserved. Default is FALSE which will reindex the chunk numerically Return Values

Returns a multidimensional numerically indexed array, starting with zero, with each dimension containing size elements.

Errors/Exceptions

If size is less than 1 E_WARNING will be thrown and NULL returned. Examples <?php $input_array = array('a', 'b', 'c', 'd', 'e'); print_r(array_chunk($input_array, 2)); print_r(array_chunk($input_array, 2, true)); ?>

The above example will output: Array ( [0] => Array ( [0] => a [1] => b ) [1] => Array ( [0] => c [1] => d ) [2] => Array ( [0] => e ) ) Array ( [0] => Array ( [0] => a [1] => b ) [1] => Array ( [2] => c [3] => d ) [2] => Array ( [4] => e ) )

array_slice — Extract a slice of the array Description array array_slice ( array $array , int $offset [, int $length = NULL [, bool $preserve_keys = false ]] ) array_slice() returns the sequence of elements from the array array as specified by the offset and length parameters. Note: This function will reset() the array pointer of the input array after use. Parameters Array - The input array. Offset - If offset is non-negative, the sequence will start at that offset in the array. If offset is negative, the sequence will start that far from the end of the array. Length - If length is given and is positive, then the sequence will have up to that many elements in it. If the array is shorter than the length, then only the available array elements will be present. If length is given and is negative then the sequence will stop that many elements from the end of the array. If it is omitted, then the sequence will have everything from offset up until the end of the array. preserve_keys

Note that array_slice() will reorder and reset the numeric array indices by default. You can change this behaviour by setting preserve_keys to TRUE.

Return Values Returns the slice. Examples <?php $input = array("a", "b", "c", "d", "e"); $output = array_slice($input, 2); // returns "c", "d", and "e" $output = array_slice($input, -2, 1); // returns "d" $output = array_slice($input, 0, 3); // returns "a", "b", and "c" // note the differences in the array keys print_r(array_slice($input, 2, -1)); print_r(array_slice($input, 2, -1, true)); ?>

The above example will output: Array ( [0] => c [1] => d ) Array ( [2] => c [3] => d )

array_splice — Remove a portion of the array and replace it with something else Description array array_splice ( array &$input , int $offset [, int $length = 0 [, mixed $replacement ]] ) Removes the elements designated by offset and length from the input array, and replaces them with the elements of the replacement array, if supplied. Note that numeric keys in input are not preserved. Note: If replacement is not an array, it will be typecast to one (i.e. (array) $parameter). This may result in unexpected behavior when using an object or NULL replacement. Parameters Input - The input array. Offset If offset is positive then the start of removed portion is at that offset from the beginning of the input array. If offset is negative then it starts that far from the end of the input array. Length If length is omitted, removes everything from offset to the end of the array. If length is specified and is positive, then that many elements will be removed. If length is specified and is negative then the end of the removed portion will be that many elements from the end of the array. Tip: to remove everything from offset to the end of the array when replacement is also specified, use count($input) for length. replacement If replacement array is specified, then the removed elements are replaced with elements from this array. If offset and length are such that nothing is removed, then the elements from the replacement array are inserted in the place specified by the offset. Note that keys in replacement array are not preserved. If replacement is just one element it is not necessary to put array() around it, unless the element is an array itself, an object or NULL. Return Values Returns the array consisting of the extracted elements. Examples Example #1 array_splice() examples <?php $input = array("red", "green", "blue", "yellow"); array_splice($input, 2); // $input is now array("red", "green") $input = array("red", "green", "blue", "yellow"); array_splice($input, 1, -1); // $input is now array("red", "yellow") $input = array("red", "green", "blue", "yellow"); array_splice($input, 1, count($input), "orange"); // $input is now array("red", "orange")

$input = array("red", "green", "blue", "yellow"); array_splice($input, -1, 1, array("black", "maroon")); // $input is now array("red", "green", "blue", "black", "maroon") $input = array("red", "green", "blue", "yellow"); array_splice($input, 3, 0, "purple"); // $input is now array("red", "green", "blue", "purple", "yellow"); ?> Example #2 array_splice() examples The following statements change the values of $input the same way: <?php array_push($input, $x, $y); array_splice($input, count($input), 0, array($x, $y)); array_pop($input); array_splice($input, -1); array_shift($input); array_splice($input, 0, 1); array_unshift($input, $x, $y); array_splice($input, 0, 0, array($x, $y)); $input[$x] = $y; // for arrays where key equals offset array_splice($input, $x, 1, $y); ?>