strtoupper - PHP code example

The PHP Function Strtoupper

The php function strtoupper is used to change the case of a string to uppercase. This function can be used to add emphasis or make a specific word stand out in your text, for example in titles of articles or web pages. It is very easy to use and is a great tool when working with text-based applications.

The strtoupper() function takes a string as its only parameter and converts it to uppercase. The letters in the string that is passed to this function will be changed to their uppercase equivalents, while all other numeric and special characters present in the string remain unchanged. This function is binary-safe.

Strings are an integral part of any web application and are very useful in many ways. One of the most common uses is capitalization. The php function strtoupper() is one of three primary capitalization related functions in the language. Other functions include strtolower() and ucwords() for converting whole strings; lcfirst() for converting just the first letter of a string, and mb_strtoupper() which can be used to convert Unicode strings that have been encoded with a multibyte character encoding.

If you've ever written any code in PHP, then chances are that you have come across the string function strtoupper(). While most developers understand the basic functionality of this function, fewer know why it is important to always add a backslash before calling this function. This is a little-known "micro-optimization" that can improve the performance of your PHP application.

strtoupper example

function redirect_canonical( $requested_url = null, $do_redirect = true ) {
    global $wp_rewrite, $is_IIS, $wp_query, $wpdb, $wp;

    if ( isset( $_SERVER['REQUEST_METHOD'] ) && ! in_array( strtoupper( $_SERVER['REQUEST_METHOD'] ), array( 'GET', 'HEAD' ), true ) ) {
        return;
    }

    /* * If we're not in wp-admin and the post has been published and preview nonce * is non-existent or invalid then no need for preview in query. */
    if ( is_preview() && get_query_var( 'p' ) && 'publish' === get_post_status( get_query_var( 'p' ) ) ) {
        if ( ! isset( $_GET['preview_id'] )
            || ! isset( $_GET['preview_nonce'] )
            || ! wp_verify_nonce( $_GET['preview_nonce'], 'post_preview_' . (int) $_GET['preview_id'] )
        )

    }

    /** * Get the request method. Overrides the Request class' method * since users expect a different answer here. * * @param bool|false $upper Whether to return in upper or lower case. */
    public function getMethod(bool $upper = false): string
    {
        return ($upper) ? strtoupper($this->method) : strtolower($this->method);
    }

    /** * Fires the actual cURL request. * * @return ResponseInterface */
    public function send(string $method, string $url)
    {
        // Reset our curl options so we're on a fresh slate.         $curlOptions = [];

    public function filter( $args = array(), $operator = 'AND' ) {
        if ( empty( $args ) ) {
            return $this->output;
        }

        $operator = strtoupper( $operator );

        if ( ! in_array( $operator, array( 'AND', 'OR', 'NOT' ), true ) ) {
            $this->output = array();
            return $this->output;
        }

        $count    = count( $args );
        $filtered = array();

        foreach ( $this->output as $key => $obj ) {
            $matched = 0;

// Numeric timezone             if ($match[8] !== '')
            {
                $timezone = $match[9] * 3600;
                $timezone += $match[10] * 60;
                if ($match[8] === '-')
                {
                    $timezone = 0 - $timezone;
                }
            }
            // Character timezone             elseif (isset($this->timezone[strtoupper($match[11])]))
            {
                $timezone = $this->timezone[strtoupper($match[11])];
            }
            // Assume everything else to be -0000             else
            {
                $timezone = 0;
            }

            // Deal with 2/3 digit years             if ($match[4] < 50)
            {

    /** * Checks to see if editor supports the mime-type specified. * * @since 3.5.0 * * @param string $mime_type * @return bool */
    public static function supports_mime_type( $mime_type ) {
        $imagick_extension = strtoupper( self::get_extension( $mime_type ) );

        if ( ! $imagick_extension ) {
            return false;
        }

        /* * setIteratorIndex is optional unless mime is an animated format. * Here, we just say no if you are missing it and aren't loading a jpeg. */
        if ( ! method_exists( 'Imagick', 'setIteratorIndex' ) && 'image/jpeg' !== $mime_type ) {
                return false;
        }

$precision = $matches[1];
                $scale = $matches[2];
            } else if (preg_match('/^float$(\d+),(\d+)$/', $row[$type], $matches)) {
                $row[$type] = 'float';
                $precision = $matches[1];
                $scale = $matches[2];
            } else if (preg_match('/^((?:big|medium|small|tiny)?int)$(\d+)$/', $row[$type], $matches)) {
                $row[$type] = $matches[1];
                // The optional argument of a MySQL int type is not precision                 // or length; it is only a hint for display width.             }
            if (strtoupper($row[$key]) == 'PRI') {
                $primary = true;
                $primaryPosition = $p;
                if ($row[$extra] == 'auto_increment') {
                    $identity = true;
                } else {
                    $identity = false;
                }
                ++$p;
            }
            $desc[$this->foldCase($row[$field])] = array(
                'SCHEMA_NAME'      => null, // @todo

if ( ! empty( $this->meta_query->queries ) ) {
            $clauses            = $this->meta_query->get_sql( 'user', $wpdb->users, 'ID', $this );
            $this->query_from  .= $clauses['join'];
            $this->query_where .= $clauses['where'];

            if ( $this->meta_query->has_or_relation() ) {
                $this->query_fields = 'DISTINCT ' . $this->query_fields;
            }
        }

        // Sorting.         $qv['order'] = isset( $qv['order'] ) ? strtoupper( $qv['order'] ) : '';
        $order       = $this->parse_order( $qv['order'] );

        if ( empty( $qv['orderby'] ) ) {
            // Default order is by 'user_login'.             $ordersby = array( 'user_login' => $order );
        } elseif ( is_array( $qv['orderby'] ) ) {
            $ordersby = $qv['orderby'];
        } else {
            // 'orderby' values may be a comma- or space-separated list.             $ordersby = preg_split( '/[,\s]+/', $qv['orderby'] );
        }

    /** * @return bool */
    public static function checkdnsrr($hostname, $type = 'MX')
    {
        if (!self::$hosts) {
            return \checkdnsrr($hostname, $type);
        }
        if (isset(self::$hosts[$hostname])) {
            $type = strtoupper($type);

            foreach (self::$hosts[$hostname] as $record) {
                if ($record['type'] === $type) {
                    return true;
                }
                if ('ANY' === $type && isset(self::$dnsTypes[$record['type']]) && 'HINFO' !== $record['type']) {
                    return true;
                }
            }
        }

        Services::routes()->loadRoutes();

        $filterCollector = new FilterCollector();

        $filters = $filterCollector->get($method, $route);

        // PageNotFoundException         if ($filters['before'] === ['<unknown>']) {
            CLI::error(
                "Can't find a route: " .
                CLI::color(
                    '"' . strtoupper($method) . ' ' . $route . '"',
                    'black',
                    'light_gray'
                ),
            );

            return EXIT_ERROR;
        }

        $tbody[] = [
            strtoupper($method),
            $route,

/** * Normalizes the method. * * @param string $method * The request method. * * @return string * The normalized request method. */
  protected function normalizeRestMethod($method) {
    return strtoupper($method);
  }

  /** * {@inheritdoc} */
  public function postSave(EntityStorageInterface $storage, $update = TRUE) {
    parent::postSave($storage, $update);

    \Drupal::service('router.builder')->setRebuildNeeded();
  }

foreach ($routes as $item) {
                $route = $item['route'] . $item['route_params'];

                // For module routing                 if ($this->prefix !== '' && $route === '/') {
                    $route = $this->prefix;
                } elseif ($this->prefix !== '') {
                    $route = $this->prefix . '/' . $route;
                }

                $tbody[] = [
                    strtoupper($item['method']) . '(auto)',
                    $route,
                    '',
                    $item['handler'],
                    $item['before'],
                    $item['after'],
                ];
            }
        }

        return $tbody;
    }

$this->leftFormula = $configuration['left_formula'];
    }

    if (!empty($configuration['extra'])) {
      $this->extra = $configuration['extra'];
    }

    if (isset($configuration['adjusted'])) {
      $this->adjusted = $configuration['adjusted'];
    }

    $this->extraOperator = strtoupper($configuration['extra_operator']);
    $this->type = $configuration['type'];
  }

  /** * {@inheritdoc} */
  public function buildJoin($select_query, $table, $view_query) {
    if (empty($this->configuration['table formula'])) {
      $right_table = $this->table;
    }
    else {

'plugins' => $js_plugins,
                'totals'  => wp_get_update_data(),
            )
        );

        if ( ! $orderby ) {
            $orderby = 'Name';
        } else {
            $orderby = ucfirst( $orderby );
        }

        $order = strtoupper( $order );

        uasort( $this->items, array( $this, '_order_callback' ) );

        $plugins_per_page = $this->get_items_per_page( str_replace( '-', '_', $screen->id . '_per_page' ), 999 );

        $start = ( $page - 1 ) * $plugins_per_page;

        if ( $total_this_page > $plugins_per_page ) {
            $this->items = array_slice( $this->items, $start, $plugins_per_page );
        }

$GUIDstring .= '-';
        $GUIDstring .= str_pad(dechex(ord($Bytestring[8])),  2, '0', STR_PAD_LEFT);
        $GUIDstring .= str_pad(dechex(ord($Bytestring[9])),  2, '0', STR_PAD_LEFT);
        $GUIDstring .= '-';
        $GUIDstring .= str_pad(dechex(ord($Bytestring[10])), 2, '0', STR_PAD_LEFT);
        $GUIDstring .= str_pad(dechex(ord($Bytestring[11])), 2, '0', STR_PAD_LEFT);
        $GUIDstring .= str_pad(dechex(ord($Bytestring[12])), 2, '0', STR_PAD_LEFT);
        $GUIDstring .= str_pad(dechex(ord($Bytestring[13])), 2, '0', STR_PAD_LEFT);
        $GUIDstring .= str_pad(dechex(ord($Bytestring[14])), 2, '0', STR_PAD_LEFT);
        $GUIDstring .= str_pad(dechex(ord($Bytestring[15])), 2, '0', STR_PAD_LEFT);

        return strtoupper($GUIDstring);
    }

    /** * @param int $FILETIME * @param bool $round * * @return float|int */
    public static function FILETIMEtoUNIXtime($FILETIME, $round=true) {
        // FILETIME is a 64-bit unsigned integer representing         // the number of 100-nanosecond intervals since January 1, 1601

        $value = (string) $value;
        if ('' === $value) {
            return;
        }

        if ('UTF-8' !== $this->charset) {
            $value = mb_convert_encoding($value, 'UTF-8', $this->charset);
        }

        $hash = strtoupper(sha1($value));
        $hashPrefix = substr($hash, 0, 5);
        $url = sprintf($this->endpoint, $hashPrefix);

        try {
            $result = $this->httpClient->request('GET', $url, ['headers' => ['Add-Padding' => 'true']])->getContent();
        } catch (ExceptionInterface $e) {
            if ($constraint->skipOnError) {
                return;
            }

            throw $e;
        }