chamilo / chamilo-lms

 * @link http://php.net/manual/en/function.substr

 * @link http://php.net/manual/en/function.mb-substr

 */

function api_substr($string, $start, $length = null, $encoding = null)

{

    if (is_null($length)) {

        $length = api_strlen($string, $encoding);

    }

    return Utf8::substr($string, $start, $length);

}

/**

 * Counts the number of substring occurrences.

 * This function is aimed at replacing the function substr_replace() for human-language strings.

 * @link http://php.net/manual/function.substr-replace

 */

function api_substr_replace($string, $replacement, $start, $length = null, $encoding = null)

{

    if (is_null($length)) {

        $length = api_strlen($string);

    }

    return UTf8::substr_replace($string, $replacement, $start, $length);

}

/**

 * Makes a string's first character uppercase.