GLib.VariantIter.next

### Method

# GLib VariantIternext

since: 2.24

#### Declaration [src]

    gboolean
    g_variant_iter_next (
      GVariantIter* iter,
      const gchar* format_string,
      ...
    )

#### Description [src]

Gets the next item in the container and unpacks it into the variable argument list according to `format_string`, returning `TRUE`.

If no more items remain then `FALSE` is returned.

All of the pointers given on the variable arguments list of this function are assumed to point at uninitialised memory. It is the responsibility of the caller to free all of the values returned by the unpacking process.

Here is an example for memory management with g_variant_iter_next():

      // Iterates a dictionary of type 'a{sv}'
      void
      iterate_dictionary (GVariant *dictionary)
      {
        GVariantIter iter;
        GVariant *value;
        gchar *key;

        g_variant_iter_init (&iter, dictionary);
        while (g_variant_iter_next (&iter, "{sv}", &key, &value))
          {
            g_print ("Item '%s' has type '%s'\n", key,
                     g_variant_get_type_string (value));

            // must free data for ourselves
            g_variant_unref (value);
            g_free (key);
          }
      }

For a solution that is likely to be more convenient to C programmers when dealing with loops, see g_variant_iter_loop().

`format_string` determines the C types that are used for unpacking the values and also determines if the values are copied or borrowed.

See the section on `GVariant` format strings.

Available since: 2.24

This method is not directly available to language bindings.

#### Parameters

`format_string`

  Type: `const gchar*`

  A GVariant format string.

  The data is owned by the caller of the method.
  The value is a NUL terminated UTF-8 string.

`...`

  Type: ``

  The arguments to unpack the value into.

#### Return value

Type: `gboolean`

`TRUE` if a value was unpacked, or `FALSE` if there as no value.