{"id":1496,"date":"2021-05-07T02:12:01","date_gmt":"2021-05-07T02:12:01","guid":{"rendered":"https:\/\/phptutorial.net\/?page_id=1496"},"modified":"2025-04-07T12:39:57","modified_gmt":"2025-04-07T12:39:57","slug":"php-strlen","status":"publish","type":"page","link":"https:\/\/www.phptutorial.net\/php-tutorial\/php-strlen\/","title":{"rendered":"PHP strlen"},"content":{"rendered":"\n

Summary<\/strong>: in this tutorial, you’ll learn how to use the PHP strlen()<\/code> function to get the length of a string.<\/p>\n\n\n\n

Introduction to the PHP strlen() function #<\/a><\/h2>\n\n\n\n

The strlen()<\/code> function returns the length of a specified string<\/a>. Here’s the syntax of the strlen()<\/code> function:<\/p>\n\n\n

strlen ( string $string ) : int<\/code><\/span>Code language:<\/span> PHP<\/span> (<\/span>php<\/span>)<\/span><\/small><\/pre>\n\n\n
The strlen()<\/code> function has one parameter $string<\/code>, which is the string to measure the length. The strlen()<\/code> function returns the length of the $string<\/code> in bytes or zero if the $string<\/code> is empty.<\/p>\n\n\n\n
It’s important to note that the strlen()<\/code> function returns the number of bytes rather than the number of characters. If each character is 1 byte, the number of bytes is the same as the number of characters.<\/p>\n\n\n\n
However, if you deal with the multibyte string, e.g., UTF-8, the number of bytes is higher than the number of characters. <\/p>\n\n\n\n
To get the number of characters in a multibyte string, you should use the mb_strlen()<\/code> function instead:<\/p>\n\n\n
mb_strlen ( string $string , string|null<\/span> $encoding = null<\/span> ) : int<\/code><\/span>Code language:<\/span> PHP<\/span> (<\/span>php<\/span>)<\/span><\/small><\/pre>\n\n\n
The mb_strlen()<\/code> function has an additional $encoding<\/code> that specifies the character encoding of the $string<\/code>.<\/p>\n\n\n\n
The mb_strlen()<\/code> function returns the number of characters in the $string<\/code> having character $encoding<\/code>. The mb_strlen()<\/code> returns one for each multibyte character.<\/p>\n\n\n\n
PHP strlen() function examples #<\/a><\/h2>\n\n\n\n
Let’s take some examples of using the strlen()<\/code> function.<\/p>\n\n\n\n
1) Simple strlen() function example #<\/a><\/h3>\n\n\n\n
The following example uses the strlen()<\/code> function to return the length of the string PHP:<\/p>\n\n\n
<?php<\/span>\n$str = 'PHP'<\/span>;\necho<\/span> strlen($str); \/\/ 3<\/span><\/code><\/span>Code language:<\/span> PHP<\/span> (<\/span>php<\/span>)<\/span><\/small><\/pre>\n\n\n
2) Using the strlen() with a multibyte string #<\/a><\/h3>\n\n\n\n
The following multibyte string has five characters. However, its size is 15 bytes.<\/p>\n\n\n
'\u3053\u3093\u306b\u3061\u306f'<\/span><\/code><\/span>Code language:<\/span> PHP<\/span> (<\/span>php<\/span>)<\/span><\/small><\/pre>\n\n\n
By the way, \u3053\u3093\u306b\u3061\u306f is a greeting in Japanese. It means hello in English.<\/p>\n\n\n\n
The strlen()<\/code> function returns 15 bytes for the string '\u3053\u3093\u306b\u3061\u306f'<\/code>:<\/p>\n\n\n
<?php<\/span>\n\n$message = '\u3053\u3093\u306b\u3061\u306f'<\/span>;\necho<\/span> strlen($message); \/\/ 15 bytes    <\/span><\/code><\/span>Code language:<\/span> PHP<\/span> (<\/span>php<\/span>)<\/span><\/small><\/pre>\n\n\n
Output:<\/p>\n\n\n
15<\/span>   <\/code><\/span>Code language:<\/span> PHP<\/span> (<\/span>php<\/span>)<\/span><\/small><\/pre>\n\n\n
But the mb_strlen()<\/code> function returns five characters for that string:<\/p>\n\n\n
<?php<\/span>\n\n$message = '\u3053\u3093\u306b\u3061\u306f'<\/span>;\necho<\/span> mb_strlen($message); \/\/ 5 characters<\/span><\/code><\/span>Code language:<\/span> PHP<\/span> (<\/span>php<\/span>)<\/span><\/small><\/pre>\n\n\n
Output:<\/p>\n\n\n
5<\/span><\/code><\/span>Code language:<\/span> PHP<\/span> (<\/span>php<\/span>)<\/span><\/small><\/pre>\n\n\n
Summary #<\/a><\/h2>\n\n\n\n
    \n
  • Use the PHP strlen()<\/code> function to get the number of bytes of a string.<\/li>\n\n\n\n
  • Use the PHP mb_strlen()<\/code> function to get the number of characters in a string with a specific encoding.<\/li>\n<\/ul>\n
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Try it<\/a><\/p>\n\n\n\n