How to Find Length of String in PHP: Simple Guide

In PHP, you can find the length of a string using the strlen() function. It returns the number of characters in the string, including spaces and special characters.

Syntax

The strlen() function takes one argument, which is the string you want to measure. It returns an integer representing the number of characters in that string.

• strlen(string $string): int
• $string: The input string whose length you want to find.
• Returns the length as an integer.

php

strlen(string $string): int

Example

This example shows how to use strlen() to find the length of different strings, including spaces and special characters.

php

<?php
$string1 = "Hello, world!";
$string2 = " PHP ";
$string3 = "12345";

echo strlen($string1) . "\n"; // Outputs 13
echo strlen($string2) . "\n"; // Outputs 5 (spaces count)
echo strlen($string3) . "\n"; // Outputs 5
?>

Output

13
5
5

Common Pitfalls

One common mistake is expecting strlen() to count characters correctly for multibyte (e.g., UTF-8) strings. strlen() counts bytes, not characters, so it may give unexpected results for non-ASCII characters.

For multibyte strings, use mb_strlen() instead.

php

<?php
// Wrong for multibyte strings
$string = "こんにちは"; // Japanese greeting
echo strlen($string) . "\n"; // Outputs 15 (bytes, not characters)

// Correct way for multibyte strings
echo mb_strlen($string, 'UTF-8') . "\n"; // Outputs 5 (characters)
?>

Output

15
5

Quick Reference

Function	Purpose	Notes
strlen()	Returns length in bytes	Use for ASCII or single-byte strings
mb_strlen()	Returns length in characters	Use for multibyte strings like UTF-8

Key Takeaways

Use strlen() to get the length of a string in PHP for simple ASCII text.

Remember strlen() counts bytes, not characters, which can cause issues with multibyte text.

Use mb_strlen() with the correct encoding for strings containing special or multibyte characters.

Spaces and special characters are counted by strlen() as part of the string length.