PHP mb_strtolower() Function Last Updated : 28 Apr, 2025 Comments Improve Suggest changes Like Article Like Report The mb_strtolower() is a PHP inbuilt function that returns lowercase alphanumeric characters. Syntax: mb_strtolower(string $string, ?string $encoding = null): stringParameters: This function accepts 2 parameters: string: This parameter specifies the lowercase string.encoding: This parameter denotes the character encoding, & in case omitted or null, then the internal character encoding value will be utilized.Return value: This function converted the uppercase string into lowercase alphanumeric characters and then returns those characters. Example 1: The following code shows the working for the mb_strtolower() function. PHP <?php $str = "GEEKSFORGEEKS" ; $str2 = mb_strtolower($str); echo $str2; ?> Output: geeksforgeeks Example 2: The following code shows the working for the mb_strtolower() function. PHP <?php $str = "Dmmm" ; $str2 = mb_strtolower($str); echo $str2; ?> Output: dmmm Reference: https://www.php.net/manual/en/function.mb-strtolower.php Comment More infoAdvertise with us Next Article PHP mb_strtolower() Function neeraj3304 Follow Improve Article Tags : PHP PHP-function PHP-Multibyte-String Similar Reads PHP mb_strstr() Function The mb_strstr() function is an inbuilt function in PHP that finds the first occurrence of a given string in the main string, i.e. it will search for the occurrence of the first needle in haystack, & id found then the portion of the haystack will be returned, otherwise return false. Syntax: mb_st 2 min read PHP mb_strlen() Function The mb_strlen() is an inbuilt PHP function that returns the string length in an integer. Syntax: mb_strlen($string, $encoding ): intParameters: This function accepts 2 parameters that are described below: $string: The string parameter whose lengths need to be determined. It is a required parameter.$ 1 min read PHP mb_strtoupper() Function The mb_strtoupper() function is an inbuilt function in PHP that helps to transform the multibyte string to uppercase. Syntax: mb_strtoupper(string $string, ?string $encoding = null): string Parameters: This function has two parameters: string: This parameter specifies the string that is to be made t 1 min read PHP mb_stristr() Function The mb_stristr() is an inbuilt function in PHP that is used to get the first occurrence of a string within another string. It will check case insensitivity. Syntax:mb_stristr( $haystack, $needle, $before_needle, $encoding = null ): string|falseParameters: This function accepts 4 parameters that are 2 min read PHP mb_strpos() Function The mb_strpos() function is an inbuilt function in PHP that finds the position of string occurrence in the string. Syntax: mb_strpos( $haystack, $needle, $offset, $encoding ): int|falseParameters: This function accepts 4 parameters that are described below: $haystack: This parameter is the main stri 2 min read PHP strtr() Function The strtr() is an inbuilt function in PHP which is used to replace a substring in a string to a given string of characters. It also has the option to change a particular word to a different word in a string. The function is case sensitive. Syntax: strtr($string, $string1, $string2) or, strtr($string 4 min read PHP strtoupper() Function The PHP strtoupper() function converts all alphabetic characters in a given string to uppercase. It takes a string as an argument and returns a new string with all letters capitalized, leaving non-alphabetic characters unchanged.Syntax string strtoupper ( $string )Parameter: The only parameter to th 2 min read PHP | ob_start() Function Let's take a quick recap. PHP is an interpreted language thus each statement is executed one after another, therefore PHP tends to send HTML to browsers in chunks thus reducing performance. Using output buffering the generated HTML gets stored in a buffer or a string variable and is sent to the buff 2 min read PHP strlen() Function The strlen() is a built-in function in PHP which returns the length of a given string.It calculates the length of the string including all the whitespaces and special characters. Syntax:strlen($string);Parameters: This parameter represents the string whose length is needed to be returned. Return Val 1 min read PHP mb_strrichr() Function The mb_strrichr() function is a case-insensitive in-built function. This function searches a multi-byte string for the last occurrence of a specified character and returns the portion of the string. Syntax: mb_strrichr( $haystack, $needle, $before_needle , $encoding) : string|falseParameters:Â This f 2 min read Like