The 27 Most Useful PHP Array Functions.

Now, we know What is Array in PHP? and how it work in PHP. After creating an array we need to  count values in array, sort arrays by their contents, convert them between strings and arrays, find unique values, search within arrays, compare arrays to other arrays and more. 

By using array functions we can easily access and manipulate an array. In following I am going to describe array function with example.

Note that the following array function is mostly used in PHP array to access and manipulate the arrays.

• is_array():

This function is used to find whether a variable is an array or not.

Syntax:

is_array($variable_name);

Example 1:

<?php 

$array=array('x','y','z'); 

if (is_array($array)){ 

echo 'Yes! It is an array.'; 

}else{

echo 'No! It is not an array.';

} 

?>

Output of the above program:

Yes! It is an array.

Example 2:

<?php 

$mark = [ 

'id' => 1027, 

'name' => 'John Abhram', 

'class' => 'Class ten', 

[ 'gender' => 'male', 

  [ 

    'bangla' => '100', 

    'english' => '95', 

    'mathematics' => '85' 

  ], 

   'country' => 'bangladesh' 

 ] 

]; 

$array1 = is_array($mark); 

$array2 = is_array($mark['roll']); 

$array3 = is_array($mark[0]); 

echo $array1 ? 'The $mark variable is an array<br>' : 'The $mark variable is not an array<br>'; 

echo $array2 ? 'The "id" key of the $mark variable is an array<br>' : 'The "id" key of the $mark variable is not an array<br>'; 

echo $array3 ? 'The 0 index of the $mark variable is an array<br>' : 'The 0 index of the $mark variable is not an array<br>'; 

?>

Output of the above program:

The $mark variable is an array<br>

The "id" key of the $mark variable is not an array<br>

The 0 index of the $mark variable is an array<br>

• in_array():

This function searches in an array for a specific value. It returns TRUE if this specific value is found in the array, or FALSE otherwise.

Syntax:

in_array($value,  $array);

Example :

<?php 

$subjects = array("English", "Mathematics", "Biology"); 

if (in_array("Mathematics", $subjects)) { 

echo "Subject Mathematics is exist"; 

} 

if (in_array("Biology", $subjects)) { 

echo "Subject mathematics is exist"; 

} 

?>

Output of the above program:

Subject Mathematics is exist

• array_unique():

This function helps to remove duplicate values from an array. The first appearance will be kept when two or more array values are the same and the other will be removed.

Syntax:

array_unique($array);

Example :

<?php 

$subjects = array("array1" => "Bangla", "English", "array2" => "Bangla", "English", "Mathematics"); 

$result = array_unique($subjects); 

print_r($result); 

?>

Output of the above program:

Array ( [array1] => Bangla [0] => English [2] => Mathematics )

• array_search():

This function search an array for a specific value and returns the key. It returns the key if the value found and false otherwise.

Syntax:

array_search($value, $array);

Example :

<?php 

$array = array("x"=>"Bangla","y"=>"Turorial","z"=>"Stars"); 

print_r(array_search("Turorial", $array)); 

?>

Output of the above program:

y

• array_reverse():

This array function return an array in reverse order with this array elements.

Syntax:

array_reverse($array);

Example 1:

<?php 

$array = array("x"=>"Bangla","y"=>"Turorial","z"=>"Stars"); 

print_r(array_reverse($array)); 

?>

Output of the above program:

Array ( [z] => Stars [y] => Turorial [x] => Bangla )

Example 2:

$array = [ 

'PHP array functions', 

'What is an array', 

'Creating Shopping cart using PHP and MySQLI', 

'Laravel Tutorials', 

'PHP array function Tutorials'

];

$array1 = array_reverse($array);

foreach ($array1 as $key => $value) { 

echo $key . ' - ' . $value . '<br>'; 

}

Output of the above program:

0 – PHP array function Tutorials

1 – Laravel Tutorials

2 – Creating Shopping cart using PHP and MySQLI 

3 – What is an array

4 – PHP array functions

• array_map(): 

This function send each value of an array to a function then multiply each value by itself and at last return an array with the new values.

Syntax:

array_map(myfunction, array1, array2, array3, ...)

Example 1:

<?php 

function myfunction($num) { 

return($num*$num); 

} 

$array = array(2,3,4,5,6); 

print_r(array_map("myfunction",$array)); 

?>

Output of the above program:

Array ( 
[0] => 1 
[1] => 4 
[2] => 9 
[3] => 16 
[4] => 25 
)

• array_diff(): 

This function compares one or more arrays and provides the values from one array, that are not present in any other arrays.

Syntax:

array_diff($arrayone, $arraytwo)

Example 1:

<?php 
$arrayone = [ 
'Google', 
'Microsoft', 
'Apple', 
'Acer', 
'Asus', 
'HP', 
'NOKIA', 
'Samsung', 
'SYMPHONY' 
]; 

$arraytwo = [ 

'Google', 

'Microsoft', 

'Apple', 

'Acer', 

'Asus', 

'HP', 

'NOKIA', 

'Samsung' 
]; 

$diff = array_diff($arrayone, $arraytwo); 

print_r($diff);

Output of the above program:

Array ( [8] => SYMPHONY )

Array Counting Functions:

There are some array functions those are related to counting values or dealing with numbers. We can count the number of values in an array and also return the maximum or minimum value and others useful operations.

• count(): 

Using this function we can know how many values are presented in a array.

Syntax:

count($array);

Example 1:

<?php 
$a[0] = 1; 
$a[1] = 3; 
$a[2] = 5; 
$result = count($a); 
print($result); 
?>

Output of the above program:

3

Example 2:

$technology = [ 
'Google', 
'Microsoft', 
'ASUS', 
'GRAMEEN PHONE', 
'BANGLALINK', 
'Juniper', 
'ACER', 
'Samsung', 
'SYMPHONY' 
];

Output of the above program:

9

• max(): 

This function finds the maximum value of an array.

Syntax:

max(array);.
or
max(value1, value2, ...);

Parameters:
array − The array with values. 
value1, value2 − The values to compare.

Example 1:

<?php 
echo (max(80, 75, 95, 100, 25, 65, 35)); 
?>

Output of the above program:

100

• min(): 

This function finds the minimum value of an array.

Syntax:

min(array);.
or
max(value1, value2, ...);

Parameters:
array − The array with values. 
value1, value2 − The values to compare.

Example 1:

<?php 
echo (max(80, 75, 95, 100, 25, 65, 35)); 
?>

Output of the above program:

25

• array_rand(): 

This function returns one or more random keys from an array.

Syntax:

array_rand(array, number).
Parameters:
array − The specific array. 
number − The number of random keys to return.

Example 1:

<?php 
$array = array("p"=>"Television","q"=>"Computer","r"=>"Radio"); 
print_r(array_rand($array)); 
?>

Output of the above program:

p

Example 2:

<?php 
$array = array("p"=>"Television","q"=>"Computer","r"=>"Radio"); 
print_r(array_rand($array, 2)); 
?>

Output of the above program:

Array ( 
[0] => p 
[1] => q 
)

• array_count_values(): 

This function count all the values of an array.

Syntax:

array_count_values($array);

Example 1:

<?php
$a=array("Television","Radio","Radio","Television","Computer");
print_r(array_count_values($a));
?>

Output of the above program:

Array ( 
[Television] => 2 
[Radio] => 2 
[Computer] => 1 
)

PHP - Sort Functions For Arrays:

• sort():

This function sort arrays in ascending order.

Syntax:

sort($array);

Example 1:

<?php 
$people = array("American", "China", "Indian"); 
sort($people); 

$array_length = count($people); 

for($i = 0; $x < $array_length; $i++) { 
echo $people[$i]; 
echo "<br>"; 
} 
?>

Output of the above program:

American
China
Indian

• rsort():

This function sort arrays in descending order.

Syntax:

rsort($array);

Example 1:

<?php 
$people = array("American", "China", "Indian"); 
rsort($people); 

$array_length = count($people); 

for($i = 0; $x < $array_length; $i++) { 
echo $people[$i]; 
echo "<br>"; 
} 
?>

Output of the above program:

Indian

China

American

• asort():

This function sort associative arrays in ascending order, according to the value.

Syntax:

asort($array);

Example 1:

<?php 
$prices = array("Computer"=>"35k", "Laptop"=>"37k", "Radio"=>"2k"); 
asort($prices); 

foreach($prices as $key => $value) { 
echo "Key=" . $key . ", Value=" . $value; 
echo "<br>"; 
} 
?>

Output of the above program:

Key=Computer, Value=35k
Key=Laptop, Value=37k
Key=Radio, Value=2k

• ksort():

This function sort associative arrays in ascending order, according to the key.

Syntax:

ksort($array);

Example 1:

<?php 
$prices = array("Computer"=>"35k", "Laptop"=>"37k", "Radio"=>"2k"); 
ksort($prices); 

foreach($prices as $key => $value) { 
echo "Key=" . $key . ", Value=" . $value; 
echo "<br>"; 
} 
?>

Output of the above program:

Key=Radio, Value=2k 
Key=Computer, Value=35k 
Key=Laptop, Value=37k

• arsort():

This function sort associative arrays in ascending order, according to the key.

Syntax:

arsort($array);

Example 1:

<?php 
$prices = array("Computer"=>"35k", "Laptop"=>"37k", "Radio"=>"2k"); 
arsort($prices); 

foreach($prices as $key => $value) { 
echo "Key=" . $key . ", Value=" . $value; 
echo "<br>"; 
} 
?>

Output of the above program:

Key=Laptop, Value=37k
Key=Computer, Value=35k
Key=Radio, Value=2k

• krsort():

This function sort associative arrays in descending order, according to the key.

Syntax:

krsort($array);

Example 1:

<?php 
$prices = array("Computer"=>"35k", "Laptop"=>"37k", "Radio"=>"2k"); 
arsort($prices); 

foreach($prices as $key => $value) { 
echo "Key=" . $key . ", Value=" . $value; 
echo "<br>"; 
} 
?>

Output of the above program:

Key=Radio, Value=2k 
Key=Laptop, Value=37k 
Key=Computer, Value=35k

Converting Between Arrays and Strings:

• implode()

This function join array elements with a string.

Syntax:

implode(separator, $array);

Example 1:

<?php 
$array = array('Hello','world','This is Tutorial', 'Stars!'); 
echo implode(" ",$array); 
?>

Output of the above program:

Hello world This is Tutorial Stars!

• explode()

This function break a string into an array.

Syntax:

explode(separator,string,limit)

Example 1:

<?php 
$array = "Hello world This is Tutorial Stars"; 
print_r (explode(" ",$array)); 
?>

Output of the above program:

Array ( 
[0] => Hello 
[1] => world 
[2] => This
[3] => is 
[4] => Tutorial
[5] => Stars 
)

General Manipulation Functions:

• array_key_exists():

This function check if the key exists in an array.

Syntax:

array_key_exists(key, array)

Example 1:

<?php 
$array = array("laptop"=>"ASUS PRO BOOK","radio"=>"Radio 2"); 
if (array_key_exists("laptop",$array)) { 
echo "This key exists."; 
} else { 
echo "This key does not exist."; 
} 
?>

Output of the above program:

This key exists.

• array_keys():

This function is used to see all of the keys of the array, but not the values.

Syntax:

array_keys($array);

Example 1:

<?php 
$array = [ 'laptop'  => 'ASUS', 'television' => 'SONY', 'motherboard'    => 'GIGABYTE', ]; 
$arrayKeys = array_keys($array); 
print_r($arrayKeys);
?>

Output of the above program:

Array ( 
[0] => laptop 
[1] => television 
[2] => motherboard 
)

• array_values():

This function is used to see all of the Values of the array, but not the Keys.

Syntax:

array_values($array);

Example 1:

<?php 
$array = [ 'laptop'  => 'ASUS', 'television' => 'SONY', 'motherboard'    => 'GIGABYTE', ]; 
$arrayValuues = array_values($array); 
print_r($arrayValuues);
?>

Output of the above program:

Array ( 
[0] => ASUS 
[1] => SONY 
[2] => GIGABYTE 
)

• array_push():

This function is used to insert values at the end of an array.

Syntax:

array_push(array, value1, value2, ...);

Example 1:

<?php 
$array = array("Computer","Laptop"); 
array_push($array,"Radio","Television"); 
print_r($array); 
?>

Output of the above program:

Array ( 
[0] => Computer 
[1] => Laptop 
[2] => Radio 
[3] => Television 
)

• array_pop():

This function is used to delete the last element of an array.

Syntax:

array_pop(array)

Example 1:

<?php 
$array = array("Computer","Laptop", "Radio"); 
array_pop($array); 
print_r($array); 
?>

Output of the above program:

Array ( 
[0] => Computer 
[1] => Laptop 
)

• array_unshift():

This function is used to insert the new element to an array.

Syntax:

array_unshift(array, value1, value2, value3, ...);

Example 1:

<?php 
$array = array("p"=>"Computer","q"=>"Radio"); 
array_unshift($array,"Television"); 
print_r($array); 
?>

Output of the above program:

Array ( [0] => Television [p] => Computer [q] => Radio )

• array_splice():

This function is used to remove elements from an array and replace it with new elements.

Syntax:

array_splice(array, start, length, array)

Example 1:

<?php 
$array1 = array("p"=>"Computer","q"=>"Laptop","r"=>"Radio","s"=>"Television"); 
$array2 = array("p"=>"Desktop","q"=>"Satteliate"); array_splice($array1,0,2,$array2); print_r($array1); 
?>

Output of the above program:

Array ( [0] => Desktop [1] => Satteliate [r] => Radio [s] => Television )

• array_merge():

This function is used to merge two arrays into one array:.

Syntax:

array_merge($array1, $array2); 

Example 1:

<?php 
$array1 = [ 'Television', 'Radio', 'Satellite' ]; 
$array2 = [ 'Telegram', 'Tutorial', 'Stars' ]; 
$combine = array_merge($array1, $array2); 
echo '<pre>'; 
print_r($combine); 
?>

Output of the above program:

Array ( 
[0] => Television 
[1] => Radio
[2] => Satellite
[3] => Telegram
[4] => Tutorial
[5] => Stars 
)