Merge pull request #2374 from jamesray1/patch-18

Create types.rst
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Yoichi Hirai 2017-06-12 11:11:59 +02:00 committed by GitHub
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@ -795,7 +795,7 @@ Mapping types are declared as ``mapping(_KeyType => _ValueType)``.
Here ``_KeyType`` can be almost any type except for a mapping, a dynamically sized array, a contract, an enum and a struct.
``_ValueType`` can actually be any type, including mappings.
Mappings can be seen as hashtables which are virtually initialized such that
Mappings can be seen as `hash tables <https://en.wikipedia.org/wiki/Hash_table>`_ which are virtually initialized such that
every possible key exists and is mapped to a value whose byte-representation is
all zeros: a type's :ref:`default value <default-value>`. The similarity ends here, though: The key data is not actually stored
in a mapping, only its ``keccak256`` hash used to look up the value.