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Type 4 – Arrays
=============================
CBOR arrays, just like :doc:`byte strings <type_2>` and :doc:`strings <type_3>`, can be encoded either as definite, or as indefinite.
Definite arrays have a fixed size which is stored in the header, whereas indefinite arrays do not and are terminated by a special "break" byte instead.
Arrays are explicitly created or decoded as definite or indefinite and will be encoded using the corresponding wire representation, regardless of whether the actual size is known at the time of encoding.
.. note:: Indefinite arrays can be conveniently used with streaming :doc:`decoding <streaming_decoding>` and :doc:`encoding <streaming_encoding>`.
================================== =====================================================================================
Corresponding :type:`cbor_type` ``CBOR_TYPE_ARRAY``
Number of allocations (definite) Two plus any manipulations with the data
Number of allocations (indefinite) Two plus logarithmically many
reallocations relative to additions
Storage requirements (definite) ``(sizeof(cbor_item_t) + 1) * size``
Storage requirements (indefinite) ``<= sizeof(cbor_item_t) + sizeof(cbor_item_t) * size * BUFFER_GROWTH``
================================== =====================================================================================
Examples
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
::
0x9f Start indefinite array
0x01 Unsigned integer 1
0xff "Break" control token
::
0x9f Start array, 1B length follows
0x20 Unsigned integer 32
... 32 items follow
Getting metadata
~~~~~~~~~~~~~~~~~
.. doxygenfunction:: cbor_array_size
.. doxygenfunction:: cbor_array_allocated
.. doxygenfunction:: cbor_array_is_definite
.. doxygenfunction:: cbor_array_is_indefinite
Reading data
~~~~~~~~~~~~~
.. doxygenfunction:: cbor_array_handle
.. doxygenfunction:: cbor_array_get
Creating new items
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
.. doxygenfunction:: cbor_new_definite_array
.. doxygenfunction:: cbor_new_indefinite_array
Modifying items
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
.. doxygenfunction:: cbor_array_push
.. doxygenfunction:: cbor_array_replace
.. doxygenfunction:: cbor_array_set
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