How To Find The Array Length PHP With Examples

The Array Length PHP is the total number of elements present on the given array elements.

In this article, we will talk about Array Length in PHP in a detailed explanation as well as example programs that could be helpful to your future projects. This topic is a continuation of the previous topic, entitled Length Of A String In PHP.

What is array length PHP?

In PHP, array length is usually about the size of an array or shall we see the number of elements were present in that array.

Further, there are two simple ways to find the number of elements present on that given array. But one of the most popular is the count() function. The count() function will return and count the elements present on that given array.

Syntax of count() function

count(array, mode)

Example

<?php
      $programmers = array("Jude","Glenn","Adones","Paul","Caren","Elijah");
      echo count($programmers);
?>

Output

6

How do you find the length of an array?

To find the array length in PHP we need to used the function count() or a sizeof() this two is a built-in function in PHP which can find the length and count the numbers element of an array and with the use of echo command together with it to find and print the length.

Example program of count() function

<?php
   $brand = array("acer","lenovo","dell","hp");
   echo count($brand);
?>

Output

4

Example program of sizeof() function

<?php
   $brand = array("acer","lenovo","dell","dell");
   echo sizeof($brand);
?>

Output

4

How many numbers can an array store?

The array can store a number of more or less 100 different values inside. An array is a storage of a list of items with just a single variable, instead of declaring a lot of variables with a value we can declare a lot of values with just only one variable.

In order to access each of the elements that were given in the array we simply use square brackets and a number inside them.

Example

<?php  
      $laptops=array("acer","hp","dell","Samsung");  
      echo "Laptops are: $laptops[0], $laptops[1], $laptops[2] and $laptops[3]";  
?> 

Output

Laptops are: acer, hp, dell and Samsung 

Is there any restriction on array length in PHP?

There is no restriction nor max on the length of the array. But there is a limit to the amount of memory that can be used in your script which can be changed on the (memory_limit) in your PHP script.

What happens if array size is exceeded?

The program will crash once the index of an array size will be exceeded.

Can we resize an array after it has been created?

The array cannot be changed once the array is already been created. The only way to resize the array is to create a new array with a fixed size and then copy all the elements from the existing array to the new array with a fixed size.

Why do we use length in array?

The length of an array can be used to fetch the highest and lowest value which present in the array object.

Does length of array start at 1?

The length of array in PHP is zero based. It means that the array started counting from zero once it was indexed and can count recursive.

Further, the index value of the first array element is 0 and the second index value is 1, and the third index value is 2, and soon.

Do arrays use a lot of memory?

The arrays use a lot of memory for the reason of they require a lot of overhead to store multi dimensional array and the element on each cell array require much memory since each array element have its own different size and type.

Which is faster array or collection?

The array is much faster rather than the collection, but still has drawbacks for too much consumption of memory. While, the collections consume less of the memory, but in terms of performance the execution is very low as compared to the arrays.

More about arrays

• How to declare an Array in PHP
• PHP in_array function With Examples
• Array Push PHP (With Detailed Explanation)
• PHP array_merge With Detailed Explanation
• PHP Remove Element From Array With Examples

Summary

In summary, you have learned about Array Length PHP. This article also discussed what array length is, how do you find the length of an array, how many numbers an array can store, restrictions on array length, what happens if the array size is exceeded, can we resize an array after it has been created, why do we use length in array, does length of array start at 1, do arrays use a lot of memory, and which is faster array or collection.

I hope this lesson has helped you learn a lot. Check out my previous and latest articles for more life-changing tutorials which could help you a lot.

Common use cases for How To Find The Array Length PHP

• Data collection loops. Build arrays from database results with foreach and $result[] = $row.
• Filter records. array_filter() to remove rows that fail a validation check.
• Transform data. array_map() to convert IDs to names, or apply a formatter to each value.
• Aggregate values. array_sum(), array_reduce(), or count() for totals and statistics.
• Sorted display. usort() with a custom comparator for domain-specific ordering.

Working code example

<?php
$orders = [
    ["id" => 1, "amount" => 250, "status" => "paid"],
    ["id" => 2, "amount" => 100, "status" => "pending"],
    ["id" => 3, "amount" => 400, "status" => "paid"],
];

// Get only paid orders
$paid = array_filter($orders, fn($o) => $o["status"] === "paid");

// Sum their amounts
$total = array_sum(array_column($paid, "amount"));
echo "Total paid: $total"; // 650
?>

Common pitfalls

• Modifying array during foreach. Never unset() or add elements during a foreach loop. Use array_filter() or build a new array.
• Numeric vs string keys. array_merge() renumbers integer keys but preserves string keys. Use + operator for key-preserving union.
• Sort in-place vs return. sort() returns bool and modifies the array; array_map() returns a new array. Read carefully.
• Empty array handling. array_reduce() on empty array returns the initial value; array_sum() returns 0.

Best practices

• Use array destructuring. [$id, $name] = explode(“,”, $csvLine) is cleaner than array indexing.
• Type declarations for functions. Declare array parameter types for type safety.
• Prefer typed arrays via generics. PHP 8+ supports @param array<int, User> PHPDoc for static analysis.
• Avoid over-nesting. Deeply nested arrays are hard to reason about. Extract to a class or DTO.

Glenn Azuelo

Programmer & Technical Writer at PIES IT Solution

Glenn Azuelo is a programmer and writer at PIES IT Solution, author of 40+ PHP tutorials, Java capstone projects, and Python game guides at itsourcecode.com. Specializes in PHP built-in functions (string manipulation, arrays, filesystem, magic methods), Java Windows Forms projects for BSIT capstone (chat application, POS, faculty management, memory game), and Python game programming with Pygame (chess, blackjack, dice).

Expertise: PHP · PHP Tutorials · PHP Built-in Functions · PHP String Functions · PHP Array Functions · PHP Magic Methods · Java · Java Swing · Windows Forms · Python · Pygame · Capstone Projects  · View all posts by Glenn Azuelo →