The accumulation objects in PHP are characterized by a length parameter to indicate the number of elements contained within it. It is necessary to estimate the length of an array in order to perform array manipulations and modifications.

sizeof() function: The sizeof() function is used to calculate all the elements present in an array or any other countable object. It can be used for both uni-dimensional as well as multi-dimensional arrays.

sizeof(arr, mode)
Parameters: This function accepts two parameters that are discussed below:

• arr – The array to count the elements.
• mode – Indicator to check whether or not to count all the elements –
• 0 – Default. Does not count all elements of multidimensional arrays
• 1 – Counts the array recursively (counts all the elements of multidimensional arrays)

<?php
$arr = array(
       "Javascript" => array(
           "C++",
           "Github"
       ),
       "Selenium"=>array(
           "Ruby"  
       ),
       "PHP"=>array(
           "CodeLobster"
       )
);
 
print_r($arr);
print("<br>");
 
echo "Sub elements of an array: "
      . sizeof($arr) . "<br>";
echo "All elements of an array: "
      . sizeof($arr, 1);
 
?>

Output:

Array (
[Javascript] => Array (
[0] => C++
[1] => Github
)
[Selenium] => Array (
[0] => Ruby
)
[PHP] => Array (
[0] => CodeLobster
)
)
Sub elements of an array: 3
All elements of an array: 7

count() function: The count() function is used to calculate all the elements in the array or any other countable object. It can be used for both uni-dimensional as well as multi-dimensional arrays.

count(arr, mode)
Parameters: This function accepts two parameters that are discussed below:

• arr – The array to count the elements.
• mode – Indicator to check whether or not to count all the elements –
• 0 – Default. Does not count all elements of multidimensional arrays
• 1 – Counts the array recursively (counts all the elements of multidimensional arrays)

<?php
$arr = array(
       "Javascript" => array(
           "C++",
          "Github"
       ),
       "Selenium" => array(
           "Ruby"  
       ),
       "PHP" => array(
           "CodeLobster"
       )
);
 
print_r($arr);
print("<br>");
 
echo "Sub elements of an array: "
      . count($arr) . "<br>";
echo "All elements of an array: "
      . count($arr, 1);
 
?>

Output

Array (
[Javascript] => Array (
[0] => C++
[1] => Github
)
[Selenium] => Array (
[0] => Ruby
)
[PHP] => Array (
[0] => CodeLobster
)
)
Sub elements of an array: 3
All elements of an array: 7