PHP Array Functions

PHP array functions are helpful to perform various complicated operations on PHP arrays. Also, PHP array functions are effortless to implement.

Read Also: PHP Arrays

Array Functions in PHP

Even though there are three types of arrays in PHP, there is no difference in applying any of the array functions to them.

The array() Function

The array() function is used to create and initialize a PHP array. This function is useful to create indexed arrays or associative arrays. PHP arrays could be single-dimensional or multidimensional.

Parameters

Syntax

array(value1,value2,value3,..etc)

Or

array(key1 => value1,key2 => value2,key3 => value3,..etc)

Example

$social_media = array("facebook","instagram","whatsapp","Telegram");
$person = array("name"=>"Nick","age"=>18,"eye color"=>"black");

The array_change_key_case() Function

This function changes the case of all keys of the array and returns an array with all its keys either in lower case or in upper case.

There are two parameters to be passed in function, which are as below.

1. CASE_LOWER – It changes the key text to lower case
2. CASE_UPPER – It changes the key text to upper case

Parameters

Syntax

array_change_key_case(array,case)

Example

<?php

$person = array("name"=>"Nick","age"=>18,"eye color"=>"black");

print_r(array_change_key_case($person,CASE_UPPER));

?>

Output

Array ( [NAME] => Nick [AGE] => 18 [EYE COLOR] => black )

The array_chunk() Function

The array_chunk() function takes an array as input and splits it into arrays of smaller chunks of the given size.

Syntax

array_chunk(array,size)

Parameters

Example

<?php

$social_media = array("facebook","instagram","whatsapp","telegram");

print_r(array_chunk($social_media,2));

?>

Output

Array ( [0] => Array ( [0] => facebook [1] => instagram ) [1] => Array ( [0] => whatsapp [1] => telegram ) )

The array_column() Function

The array_column() function returns the values from a single column of the input array and is identified by the column_key.

Syntax

array_column(array,column_key,index_key)

Parameters

Note: The column_key is the key element of the array, and Index_key is an optional field.

Example

<?php

$person = array(

array(

    "name"=>"Nick",

    "age"=>18,

    "eye color"=>"black",

    ),

array(

    "name"=>"Monil",

    "age"=>19,

    "eye color"=>"blue",

    ),

array(

    "name"=>"Yash",

    "age"=>22,

    "eye color"=>"black",

    )

);

$_names = array_column($person, 'name');

print_r($_names);

?>

Output

Array ( [0] => Nick [1] => Monil [2] => Yash )

The array_combine() Function

This function takes two different or the same arrays as input and creates a new array by using the values from the key array as keys and the values from the values array as the corresponding values.

Syntax

array_combine(keys,values)

Parameters

Example

<?php

$name=array("Nick","Yash","Monil");

$score=array(21,19,19);

print_r(array_combine($name,$score));

?>

Output

Array ( [Nick] => 21 [Yash] => 19 [Monil] => 19 )

The array_count_values() Function

The array_count_values() function returns an associative array of values using the values of the input array as keys and their frequency in the input array as values.

Syntax

array_count_values(array)

Parameters

Example

<?php

$x = array("a","b","c","a","a","b");

print_r(array_count_values($x));

?>

Output

Array ( [a] => 3 [b] => 2 [c] => 1 )

The array_diff() Function

The array_diff() function compares array1 against one or more other arrays passed to it and returns the values in array1 that are not present in any of the other arrays.

Syntax

array_diff(arr1,arr2,…etc)

Parameters

Example

<?php

$x1 = array("1","2","3","4");

$x2 = array("1","2","4");

print_r(array_diff($x1,$x2));

?>

Output

Array ( [2] => 3 )

The array_diff_assoc() Function

The function compares two or more arrays and returns the difference.

This function compares the keys and the values of two (or more) arrays and returns an array that contains the entries from array1 but that are not present in array2 or array3, etc.

This function is different from than array_diff() function because array_diff() uses only values to compare with other arrays, whereas the array_diff_assoc() function uses keys and values while comparing with other arrays.

Syntax

array_diff_assoc(arr1,arr2,…etc)

Parameters

Example

$x1 = array("1"=>"Nick","2"=>"Yash","3"=>"Monil","4"=>"Shubham");
$x2 = array("1"=>"Nick","2"=>"Monil","3"=>"Monil");
print_r(array_diff_assoc($x1,$x2));

Output

Array ( [2] => Yash [4] => Shubham )

The array_diff_key() Function

The array_diff_key() function compares the keys from array1 against the keys from array2, array3…etc and returns an array having the difference, i.e. the keys which are available in array1 and not available in array2, array3…etc. This function is like the array_diff() function except the comparison is done based on the keys instead of the values.

Syntax

array_diff_key(arr1,arr2,…etc)

Parameters

Example

<?php

$x1 = array("1"=>"Nick","2"=>"Yash","3"=>"Monil","4"=>"Shubham");

$x2 = array("1"=>"Nick","2"=>"Monil","3"=>"Monil");

print_r(array_diff_key($x1,$x2));

?>

Output

Array ( [4] => Shubham )

The array_fill() Function

It fills an array with num entries of the value parameter, keys starting at the start_index parameter.

Syntax

array_fill(index,number,value)

Parameters

Note:

• The index parameter indicates the index no from where we want to start the index.
• The number parameter indicates the number of elements from where we want to insert.
• The value parameter is the value of the position.

Example

<?php

$x = array_fill(2,3,"Errorsea");

print_r($x);

?>

Output

Array ( [2] => Errorsea [3] => Errorsea [4] => Errorsea)

The array_fill_keys() function

The array_fill_keys() function returns a new array with the key values of the passed array and sets the value of each key as the specified value.

Syntax

array_fill_keys(keys, value)

Parameters

Example

<?php

$name=array("Nick","Yash","Monil");

print_r(array_fill_keys($name,18));

?>

Output

Array ( [Nick] => 18 [Yash] => 18 [Monil] => 18 )

The array_flip() Function

It returns an array in flip order, i.e. keys from input become values and values from input become keys.

Syntax

array_flip(array)

Parameters

Example

<?php

$x = array("name"=>"Nick","age"=>18,"eye color"=>"black");

print_r(array_flip($x));

?>

Output

Array ( [Nick] => name [18] => age [black] => eye color )

The array_intersect() Function

The array_intersect() function is used to compare the values of the two arrays and is used to return the common terms.

Syntax

array_intersect(arr1,arr2,…etc)

Parameters

Example

<?php

$x1 = array(1,2,3,4);

$x2 = array(1,2,4);

print_r(array_intersect($x1,$x2));

?>

Output

Array ( [0] => 1 [1] => 2 [3] => 4 )

The array_intersect_assoc() Function

The array_intersect_assoc() function is used to compare the keys and the values of the two arrays, and it returns the matches.

Syntax

array_intersect_assoc(arr1,arr2,…etc)

Parameters

Example

<?php

$x1 = array("1"=>"Nick","2"=>"Yash","3"=>"Monil","4"=>"Shubham");

$x2 = array("1"=>"Nick","2"=>"Monil","3"=>"Monil");

print_r(array_intersect_assoc($x1,$x2));

?>

Output

Array ( [1] => Nick [3] => Monil )

The array_intersect_key() Function

The array_intersect_key() function is useful to compare the keys of the two arrays, and it returns the matches.

Syntax

array_intersect_key(arr1,arr2,…etc)

Parameters

Example

<?php

$x1 = array("1"=>"Nick","2"=>"Yash","3"=>"Monil","4"=>"Shubham");

$x2 = array("1"=>"Nick","3"=>"Monil");

print_r(array_intersect_key($x1,$x2));

?>

Output

Array ( [1] => Nick [3] => Monil )

The array_key_exists() Function

The array_key_exist() function is useful to search a particular key in the array. It returns true if the key is present in the array. It returns false if the key isn’t present in the array.

Syntax

array_key_exists(key,array)

Parameters

Example

<?php

$x = array("name"=>"Nick","age"=>18,"eye color"=>"black");

if(array_key_exists("name",$x))

{

    echo "key is present";

}else{

    echo "key isn’t present";

}

?>

Output

key is present

The array_keys() Function

The array_keys() function returns the array keys of the specified array.

Syntax

array_keys(array,value,strict)

Parameters

Note: Here, value and strict fields are optional.

Example

$x = array("name"=>"Nick","age"=>18,"eye color"=>"black");
print_r(array_keys($x));

Output

Array ( [0] => name [1] => age [2] => eye color )

The array_map() Function

This function is used for sending values of the array to a user-created function and returns the array with new values.

Syntax

array_map(function,arr1,arr2,…etc)

Parameters

Example

<?php

$x = array(1,2,4);

function cube($m)

{

    Return $m*$m*$m;

}

print_r(array_map(cube,$x));

?>

Output

Array ( [0] => 1 [1] => 8 [2] => 64 )

The array_merge() Function

The array_merge() function is used to merge two or more arrays.

Syntax

array_merge(arr1,arr2,…etc)

Parameters

Example

<?php

$x1 = array(1,2,4);

$x2 = array(6,7);

print_r(array_merge($x1,$x2));

?>

Output

Array ( [0] => 1 [1] => 2 [2] => 4 [3] => 6 [4] => 7 )

The array_multisort() Function

The array_multisort() function returns the sorted array in ascending order.

Parameters

Example

<?php

$x = array("a","y","c","k","h","z");

array_multisort($x);

print_r($x);

?>

Output

Array ( [0] => a [1] => c [2] => h [3] => k [4] => y [5] => z )

The array_pad() Function

It returns a copy of the array padded to the size specified by pad_size with value pad_value.

Syntax

array_pad(array,size,value)

Parameters

Example

<?php

$x = array("Yash","Nick","Monil");

print_r(array_pad($x,5,"Errorsea"));

?>

Output

Array ( [0] => Yash [1] => Nick [2] => Monil [3] => Errorsea [4] => Errorsea )

The array_product() Function

The array_product() function returns the product of array elements.

Syntax

array_product(array)

Parameters

Example

<?php

$x = array(2,5);

print_r(array_product($x));

?>

Output

10

The array_push() Function

This function treats the array as a stack and pushes the passed variables var1, var2… onto the end of the array.

Syntax

array_push(array,val2,val2,…etc)

Parameters

Example

<?php

$x = array(1,8,3);

array_push($x,4,6);

print_r($x);

?>

Output

Array ( [0] => 1 [1] => 8 [2] => 3 [3] => 4 [4] => 6 )

The array_pop() Function

The function pops and returns the last value of the array.

Syntax

array_pop(array)

Parameters

Example

<?php

$x = array(1,2,3);

array_pop($x);

print_r($x);

?>

Output

Array ( [0] => 1 [1] => 2 )

The array_rand() Function

The array_rand() function returns the random keys from the array. We can specify the number of random keys we want.

Parameters

Example

<?php

$x = array(1,2,3,4,5);

$random = array_rand($x,2);

echo $x[$random[0]]."<br>";

echo $x[$random[1]];

?>

Output

3
4

The array_replace() Function

The array_replace() function replaces the values of the first array with the values of the second array.

Syntax

array_replace(arr1,arr2)

Example

<?php

$x1 =array(1,2);

$x2 =array(3,4);

print_r(array_replace($x1,$x2));

?>

Output

Array ( [0] => 3 [1] => 4 )

The array_reverse() Function

This function reverses the order of all the elements of a padded array.

Parameters

Syntax

array_reverse(array)

Example

<?php

$x = array(“A”,”B”,”C”);

print_r(array_reverse($x));

?>

Output

Array ( [0] => C [1] => B [2] => A )

The array_search() Function

The array_search() function is used to search the value in the array. It returns the key position of the matching element.

Syntax

array_search(value, array, strict)

Parameters

Note: Here, strict is an optional field.

Example

<?php

$x = array("name"=>"Nick","age"=>18,"eye color"=>"black");

echo array_search("Nick",$x);

?>

Output

name

The array_shift() Function

This function shifts the first value of the array off and returns it, shortening the array by one element and moving everything down.

Syntax

array_shift(array)

Parameters

Example

<?php

$x = array(1,2,3,4,5);

echo array_shift($x)."<br>";

print_r($x);

?>

Output

1
Array ( [0] => 2 [1] => 3 [2] => 4, [3] => 5 )

The array_slice() Function

The function returns the sequence of elements from the array as specified by the offset and length parameters.

Syntax

array_slice(array, start, length, preserve)

Parameters

Note: Here length and preserve are optional fields.

Example

<?php

$person = array("yash","monil","Nick","Shubham");

print_r(array_slice($person,2));

?>

Output

Array ( [0] => Nick [1] => Shubham )

The array_splice() Function

This function removes the elements designated by offset and length from the input array, and replaces them with the elements of the replacement array, if supplied. It returns an array containing the extracted elements.

Syntax

array_splice(array, start, length, array)

Parameters

Example

<?php

$person = array("yash","monil","Nick","Shubham");

$x = array(1,2);

array_splice($person,0,2,$x);

print_r($person);

?>

Output

Array ( [0] => 1 [1] => 2 [2] => Nick [3] => Shubham )

The array_sum() Function

It calculates the sum of values in an array and returns the sum of values in an array as an integer or float.

Syntax

array_sum(array)

Parameters

Example

<?php

$x = array(1,2,3,4,5);

echo array_sum($x);

?>

Output

15

The array_values() Function

This function returns all the values from the input array and indexes numerically the array.

Syntax

array_values ( $array )

Parameters

Example

<?php

$x = array("name"=>"Nick","age"=>18,"eye color"=>"black"); 

print_r(array_values($x));

?>

Output

Array ( [0] => Nick [1] => 18 [2] => black )

The array_walk() Function

This function returns an array containing all the values of array1 that are present in all the arguments array2, array3.

Syntax

array_walk(array,function)

Parameters

Example

<?php

function test($val,$key)

{

    echo "The key $key has the value $val<br>";

}

$x=array("name"=>"Nick","age"=>18,"eye color"=>"black");

array_walk($x, "test");

?>

Output

The key name has the value Nick
The key age has the value 18
The key eye color has the value black

The asort() Function

This function sorts an array such that array indices maintain their correlation with the array elements they are associated with. This is used mainly when sorting associative arrays where the actual element order is significant. The adsort() function is an alternative for the asort() function.

Syntax

asort(array,sort_type)

Parameters

Example

<?php

$person = array("yash" => 18 , "Nick" => 21 , "Monil" => 15 );

asort($person);

foreach($person as $x=>$x_value)

{

    echo "Key=" . $x . ", Value=" . $x_value."<br>";

}

?>

Output

Key=Monil, Value=15
Key=yash, Value=18
Key=Nick, Value=21

The compact() Function

This function takes a variable number of parameters. Each parameter can be either a string containing the name of the variable, or an array of variable names.

Syntax

compact(var1,var2,….)

Parameters

Example

<?php

$name="Nick";

$age=20;

$eye_colour = "black";

print_r(compact("name","age","eye_colour"));

?>

Output

Array ( [name] => Nick [age] => 20 [eye colour] => black )

The count() Function

In this function if the optional mode parameter is set to COUNT_RECURSIVE (or 1), count() will recursively count the array.

Syntax

count(array, mode)

Parameters

Node: The mode is an optional field

Example

<?php

$m = array(1,2,3,5,6);

echo count($m);

?>

Output

5

The current() Function

Every array has an internal pointer to its “current” element, which is initialized to the first element inserted into the array.

Syntax

current(array)

Parameters

Example

<?php
$m = array(1,2,3,5,6);
echo current($m);
?>

Output

1

The each() Function

The each() function returns the current key and value pair from the array and advances the array cursor. This pair is returned in a four-element array, with the keys 0, 1, key, and value. Elements 0 and key contain the key name of the array element, and 1 and value contain the data.

Syntax

each(array)

Parameters

Example

<?php

$x = array("yash" => 18 , "Nick" => 21 , "Monil" => 15 );

print_r(each($x));

?>

Output

Array ( [1] => 18 [value] => 18 [0] => yash [key] => yash )

The end() Function

This function moves the internal pointer to the last element and returns it.

Syntax

end(array)

Parameters

Example

<?php
$x = array("yash", "Nick" , "Monil" );
echo end($x);
?>

Output

Monil

The in_array() Function

This function searches an array for a specific value.

Note:

• It returns true if the key is present in the array.
• It returns false if the key isn’t present in the array.

Syntax

in_array(search, array,type)

Parameters

Example

<?php

$x = array(1,2,3,4,5);

if(array_key_exists(4,$x))

{

   echo " Value is present";

}else{

   echo "Value isn’t present";

}

?>

Output

Value is present

The key() Function

The key() function returns the element key from the current internal pointer position.

Syntax

key(array)

Parameters

Example

<?php

$x = array("Yash" => 18 , "Nick" => 21 , "Monil" => 15 );

echo "key is " .key($x);

?>

Output

key is Yash

The krsort() Function

This function sorts an array by the keys in reverse order. The values keep their original keys.

Syntax

krsort(array,sort_type)

Parameters

Example

<?php

$person = array("Yash" => 18 , "Nick" => 21 , "Monil" => 15 );

krsort($person);

foreach($person as $x=>$x_value)

{

    echo "Key=" . $x . ", Value=" . $x_value."<br>";

}

?>

Output

Key=Yash, Value=18
Key=Nick, Value=21
Key=Monil, Value=15

The ksort() Function

This function sorts the array by key, maintaining key to data correlations. This is useful mainly for associative arrays.

Syntax

ksort(array,sort_type)

Parameters

Example

<?php

$person = array("Yash" => 18 , "Nick" => 21 , "Monil" => 15 );

ksort($person);

foreach($person as $x=>$x_value)

{

    echo "Key=" . $x . ", Value=" . $x_value."<br>";

}

?>

Output

Key=Monil, Value=15
Key=Nick, Value=21
Key=Yash, Value=18

The list() Function

Like array(), this is not really a function, but a language construct. list() is used to assign a list of variables in one operation.

Syntax

list(val1,val2,….)

Parameters

Example

<?php

$x = array(“Yash”,”Nick”,”Monil”);

list($a,$b,$c) = $x;

echo $a.” “.$b.” “.$c;

?>

Output

Yash Nick Monil

The next() Function

This function returns the array value in the next place or FALSE if there are no more elements.

Syntax

next(array)

Parameters

Example

<?php

$x = array("Yash","Nick","Monil");

echo(next($x));

?>

Output

Nick

The pos() Function

This function returns the value of the array element. The function does not move the pointer. If the pointer points beyond the end of the elements list, pos() returns FALSE.

Syntax

pos(array)

Parameters

Example

<?php

$x = array("Yash","Nick","Monil");

echo(pos($x));

?>

Output

Yash

The prev() Function

This function returns the array value in the previous place or FALSE if there are no more elements.

Syntax

prev(array)

Parameters

Example

<?php

$x = array("Yash","Nick","Monil");

echo(current($x))."<br>";

echo(next($x))."<br>";

echo(prev($x));

?>

Output

Yash
Nick
Yash

The range() Function

The function returns an array of elements from low to high, inclusive. If low > high, the sequence will be from high to low.

Syntax

range(low,high)

Parameters

Example

<?php

print_r(range(1,3));

?>

Output

Array ( [0] => 1 [1] => 2 [2] => 3 )

The reset() Function

The reset() function rewinds the array’s internal pointer to the first element and returns the value of the first array element, or FALSE if the array is empty.

Syntax

reset(array)

Parameters

Example

<?php

$x = array("Yash","Nick","Monil");

echo(current($x))."<br>";

echo(next($x))."<br>";

echo(reset($x));

?>

Output

Yash
Nick
Yash

The sort() Function

The sort() function sorts an array. In this function, the Elements will be arranged from lowest to highest.

Syntax

sort(array,sort_type)

Parameters

Example

<?php

$x = array("Yash","Nick","Monil");

sort($x);

print_r($x);

?>

Output

Array ( [0] => Monil [1] => Nick [2] => Yash )

The rsort() Function

The rsort() function sorts the indexed array in descending order.

Syntax

rsort(array,sort_type)

Parameters

Example

<?php

$x = array("Yash","Nick","Monil");

rsort($x);

print_r($x);

?>

Output

Array ( [0] => Yash [1] => Nick [2] => Monil )

The shuffle() Function

This function shuffles an array. It assigns new keys for the elements in the array. It removes any existing keys you may have assigned, rather than just reordering the keys.

Syntax

shuffle(array)

Parameters

Example

<?php

$x = array("Yash","Nick","Monil");

shuffle($x);

print_r($x);

?>

Output

Array ( [0] => Nick [1] => Monil [2] => Yash )

The sizeof() Function

In this function iff, the optional mode parameter is set to COUNT_RECURSIVE sizeof() will recursively count the array. The function is useful for counting all the elements of a multidimensional array. The default value for mode is 0.

Syntax

sizeof(array,mode)

Parameters

Example

<?php

$x = array("Yash","Nick","Monil");

echo sizeof($x);

?>

Output

3

Read More: PHP Superglobals

Conclusion

These are the different types of array function which are useful in learning PHP programming. We hope we have been able to help you have in gaining a basic understanding of PHP array functions. 

Enjoy Programming 🙂