|  | Home · All Classes · Modules

# QHostAddress Class Reference
[QtNetwork module]

The QHostAddress class provides an IP address. More...

### Types

- enum SpecialAddress { Null, Broadcast, LocalHost, LocalHostIPv6, Any, AnyIPv6 }

### Methods

- __init__ (self)
- __init__ (self, SpecialAddress address)
- __init__ (self, unsigned long ip4Addr)
- __init__ (self, QString address)
- __init__ (self, QHostAddress copy)
- clear (self)
- bool isNull (self)
- QAbstractSocket.NetworkLayerProtocol protocol (self)
- QString scopeId (self)
- setAddress (self, unsigned long ip4Addr)
- bool setAddress (self, QString address)
- setScopeId (self, QString id)
- unsigned long toIPv4Address (self)
- QString toString (self)

### Special Methods

- bool __eq__ (self, QHostAddress address)
- bool __eq__ (self, SpecialAddress address)
- bool __ne__ (self, QHostAddress address)
- bool __ne__ (self, SpecialAddress address)

## Detailed Description

The QHostAddress class provides an IP address.

This class holds an IPv4 or IPv6 address in a platform- and protocol-independent manner.

QHostAddress is normally used with the QTcpSocket, QTcpServer, and QUdpSocket to connect to a host or to set up a server.

A host address is set with setAddress(), checked for its type using isIPv4Address() or isIPv6Address(), and retrieved with toIPv4Address(), toIPv6Address(), or toString().

The class also supports common predefined addresses: Null, LocalHost, LocalHostIPv6, Broadcast, and Any.

See also QTcpSocket, QTcpServer, and QUdpSocket.

## Type Documentation

### QHostAddress.SpecialAddress

Constant | Value | Description
--- | --- | ---
`QHostAddress.Null` | `0` | The null address object. Equivalent to QHostAddress().
`QHostAddress.LocalHost` | `2` | The IPv4 localhost address. Equivalent to QHostAddress("127.0.0.1").
`QHostAddress.LocalHostIPv6` | `3` | The IPv6 localhost address. Equivalent to QHostAddress(".1").
`QHostAddress.Broadcast` | `1` | The IPv4 broadcast address. Equivalent to QHostAddress("255.255.255.255").
`QHostAddress.Any` | `4` | The IPv4 any-address. Equivalent to QHostAddress("0.0.0.0").
`QHostAddress.AnyIPv6` | `5` | The IPv6 any-address. Equivalent to QHostAddress(".").

## Method Documentation

### QHostAddress.__init__ (self)

Constructs a host address object with the IP address 0.0.0.0.

See also clear().

### QHostAddress.__init__ (self, SpecialAddress address)

Constructs a host address object with the IPv4 address ip4Addr.

### QHostAddress.__init__ (self, unsigned long ip4Addr)

Constructs a host address object with the IPv6 address ip6Addr.

ip6Addr must be a 16-byte array in network byte order (big endian).

### QHostAddress.__init__ (self, QString address)

Constructs a host address object with the IPv6 address ip6Addr.

### QHostAddress.__init__ (self, QHostAddress copy)

Constructs an IPv4 or IPv6 address using the address specified by the native structure sockaddr.

See also setAddress().

### QHostAddress.clear (self)

Sets the host address to 0.0.0.0.

### bool QHostAddress.isNull (self)

Returns true if this host address is null (INADDR_ANY or in6addr_any). The default constructor creates a null address, and that address is not valid for any host or interface.

### QAbstractSocket.NetworkLayerProtocol QHostAddress.protocol (self)

Returns the network layer protocol of the host address.

### QString QHostAddress.scopeId (self)

Returns the scope ID of an IPv6 address. For IPv4 addresses, or if the address does not contain a scope ID, an empty QString is returned.

The IPv6 scope ID specifies the scope of reachability for non-global IPv6 addresses, limiting the area in which the address can be used. All IPv6 addresses are associated with such a reachability scope. The scope ID is used to disambiguate addresses that are not guaranteed to be globally unique.

IPv6 specifies the following four levels of reachability:

- Node-local: Addresses that are only used for communicating with services on the same interface (e.g., the loopback interface ".1").
- Link-local: Addresses that are local to the network interface (link). There is always one link-local address for each IPv6 interface on your host. Link-local addresses ("fe80...") are generated from the MAC address of the local network adaptor, and are not guaranteed to be unique.
- Site-local: Addresses that are local to the site / private network (e.g., the company intranet). Site-local addresses ("fec0...") are usually distributed by the site router, and are not guaranteed to be unique outside of the local site.
- Global: For globally routable addresses, such as public servers on the Internet.

When using a link-local or site-local address for IPv6 connections, you must specify the scope ID. The scope ID for a link-local address is usually the same as the interface name (e.g., "eth0", "en1") or number (e.g., "1", "2").

This function was introduced in Qt 4.1.

See also setScopeId().

### QHostAddress.setAddress (self, unsigned long ip4Addr)

Set the IPv4 address specified by ip4Addr.

### bool QHostAddress.setAddress (self, QString address)

This is an overloaded member function, provided for convenience.

Set the IPv6 address specified by ip6Addr.

ip6Addr must be an array of 16 bytes in network byte order (high-order byte first).

### QHostAddress.setScopeId (self, QString id)

Sets the IPv6 scope ID of the address to id. If the address protocol is not IPv6, this function does nothing.

This function was introduced in Qt 4.1.

See also scopeId().

### unsigned long QHostAddress.toIPv4Address (self)

Returns the IPv4 address as a number.

For example, if the address is 127.0.0.1, the returned value is 2130706433 (i.e. 0x7f000001).

This value is only valid if isIp4Addr() returns true.

See also toString().

### QString QHostAddress.toString (self)

Returns the address as a string.

For example, if the address is the IPv4 address 127.0.0.1, the returned string is "127.0.0.1".

See also toIPv4Address().

### bool QHostAddress.__eq__ (self, QHostAddress address)

### bool QHostAddress.__eq__ (self, SpecialAddress address)

### bool QHostAddress.__ne__ (self, QHostAddress address)

### bool QHostAddress.__ne__ (self, SpecialAddress address)