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| -rw-r--r-- | docs/types.rst | 38 |
1 files changed, 38 insertions, 0 deletions
diff --git a/docs/types.rst b/docs/types.rst index 1d027d23..62164c0f 100644 --- a/docs/types.rst +++ b/docs/types.rst @@ -356,6 +356,44 @@ the ``.length`` member. } } +.. index:: ! array;literals, !inline;arrays + +Array Literals / Inline Arrays +^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ + +Array literals are arrays that are written as an expression and are not +assigned to a variable right away. + +:: + + contract C { + function f() { + g([uint(1), 2, 3]); + } + function g(uint[3] _data) { + // ... + } + } + +The type of an array literal is a memory array of fixed size whose base +type is the common type of the given elements. The type of ``[1, 2, 3]`` is +``uint8[3] memory``, because the type of each of these constants is ``uint8``. +Because of that, it was necessary to convert the first element in the example +above to ``uint``. Note that currently, fixed size memory arrays cannot +be assigned to dynamically-sized memory arrays, i.e. the following is not +possible: + +:: + + contract C { + function f() { + // The next line creates a type error because uint[3] memory + // cannot be converted to uint[] memory. + uint[] x = [uint(1), 3, 4]; + } + +It is planned to remove this restriction in the future but currently creates +some complications because of how arryes are passed in the ABI. .. index:: ! array;length, length, push, !array;push |