# URI Class

The URI Class provides methods that help you retrieve information from your URI strings. If you use URI routing, you can also retrieve information about the re-routed segments.

Note

This class is initialized automatically by the system so there is no need to do it manually.

## Class Reference

class CI_URI
  segment($n[, $no_result = NULL])
    Parameters:

      - $n (`int`) – Segment index number

      - $no_result (`mixed`) – What to return if the searched segment is not found

    Returns:

      Segment value or $no_result value if not found

    Return type:

      `mixed`

    Permits you to retrieve a specific segment. Where n is the segment number you wish to retrieve. Segments are numbered from left to right. For example, if your full URL is this:

        http://example.com/index.php/news/local/metro/crime_is_up

    The segment numbers would be this:

    1. news

    2. local

    3. metro

    4. crime_is_up

    The optional second parameter defaults to NULL and allows you to set the return value of this method when the requested URI segment is missing. For example, this would tell the method to return the number zero in the event of failure:

        $product_id = $this->uri->segment(3, 0);

    It helps avoid having to write code like this:

        if ($this->uri->segment(3) === FALSE)
        {
                $product_id = 0;
        }
        else
        {
                $product_id = $this->uri->segment(3);
        }

  rsegment($n[, $no_result = NULL])
    Parameters:

      - $n (`int`) – Segment index number

      - $no_result (`mixed`) – What to return if the searched segment is not found

    Returns:

      Routed segment value or $no_result value if not found

    Return type:

      `mixed`

    This method is identical to `segment()`, except that it lets you retrieve a specific segment from your re-routed URI in the event you are using CodeIgniter’s URI Routing feature.

  slash_segment($n[, $where = 'trailing'])
    Parameters:

      - $n (`int`) – Segment index number

      - $where (`string`) – Where to add the slash (‘trailing’ or ‘leading’)

    Returns:

      Segment value, prepended/suffixed with a forward slash, or a slash if not found

    Return type:

      `string`

    This method is almost identical to `segment()`, except it adds a trailing and/or leading slash based on the second parameter. If the parameter is not used, a trailing slash added. Examples:

        $this->uri->slash_segment(3);
        $this->uri->slash_segment(3, 'leading');
        $this->uri->slash_segment(3, 'both');

    Returns:

    1. segment/

    2. /segment

    3. /segment/

  slash_rsegment($n[, $where = 'trailing'])
    Parameters:

      - $n (`int`) – Segment index number

      - $where (`string`) – Where to add the slash (‘trailing’ or ‘leading’)

    Returns:

      Routed segment value, prepended/suffixed with a forward slash, or a slash if not found

    Return type:

      `string`

    This method is identical to `slash_segment()`, except that it lets you add slashes a specific segment from your re-routed URI in the event you are using CodeIgniter’s URI Routing feature.

  uri_to_assoc([$n = 3[, $default = array()]])
    Parameters:

      - $n (`int`) – Segment index number

      - $default (`array`) – Default values

    Returns:

      Associative URI segments array

    Return type:

      `array`

    This method lets you turn URI segments into an associative array of key/value pairs. Consider this URI:

        index.php/user/search/name/joe/location/UK/gender/male

    Using this method you can turn the URI into an associative array with this prototype:

        [array]
        (
                'name'          => 'joe'
                'location'      => 'UK'
                'gender'        => 'male'
        )

    The first parameter lets you set an offset, which defaults to 3 since your URI will normally contain a controller/method pair in the first and second segments. Example:

        $array = $this->uri->uri_to_assoc(3);
        echo $array['name'];

    The second parameter lets you set default key names, so that the array returned will always contain expected indexes, even if missing from the URI. Example:

        $default = array('name', 'gender', 'location', 'type', 'sort');
        $array = $this->uri->uri_to_assoc(3, $default);

    If the URI does not contain a value in your default, an array index will be set to that name, with a value of NULL.

    Lastly, if a corresponding value is not found for a given key (if there is an odd number of URI segments) the value will be set to NULL.

  ruri_to_assoc([$n = 3[, $default = array()]])
    Parameters:

      - $n (`int`) – Segment index number

      - $default (`array`) – Default values

    Returns:

      Associative routed URI segments array

    Return type:

      `array`

    This method is identical to `uri_to_assoc()`, except that it creates an associative array using the re-routed URI in the event you are using CodeIgniter’s URI Routing feature.

  assoc_to_uri($array)
    Parameters:

      - $array (`array`) – Input array of key/value pairs

    Returns:

      URI string

    Return type:

      `string`

    Takes an associative array as input and generates a URI string from it. The array keys will be included in the string. Example:

        $array = array('product' => 'shoes', 'size' => 'large', 'color' => 'red');
        $str = $this->uri->assoc_to_uri($array);

        // Produces: product/shoes/size/large/color/red

  uri_string()
    Returns:

      URI string

    Return type:

      `string`

    Returns a string with the complete URI. For example, if this is your full URL:

        http://example.com/index.php/news/local/345

    The method would return this:

        news/local/345

  ruri_string()
    Returns:

      Routed URI string

    Return type:

      `string`

    This method is identical to `uri_string()`, except that it returns the re-routed URI in the event you are using CodeIgniter’s URI Routing feature.

  total_segments()
    Returns:

      Count of URI segments

    Return type:

      `int`

    Returns the total number of segments.

  total_rsegments()
    Returns:

      Count of routed URI segments

    Return type:

      `int`

    This method is identical to `total_segments()`, except that it returns the total number of segments in your re-routed URI in the event you are using CodeIgniter’s URI Routing feature.

  segment_array()
    Returns:

      URI segments array

    Return type:

      `array`

    Returns an array containing the URI segments. For example:

        $segs = $this->uri->segment_array();

        foreach ($segs as $segment)
        {
                echo $segment;
                echo '<br />';
        }

  rsegment_array()
    Returns:

      Routed URI segments array

    Return type:

      `array`

    This method is identical to `segment_array()`, except that it returns the array of segments in your re-routed URI in the event you are using CodeIgniter’s URI Routing feature.