diff options
Diffstat (limited to 'docs')
| -rw-r--r-- | docs/contracts.rst | 6 | ||||
| -rw-r--r-- | docs/frequently-asked-questions.rst | 9 | ||||
| -rw-r--r-- | docs/miscellaneous.rst | 2 | ||||
| -rw-r--r-- | docs/security-considerations.rst | 3 | ||||
| -rw-r--r-- | docs/types.rst | 31 |
5 files changed, 10 insertions, 41 deletions
diff --git a/docs/contracts.rst b/docs/contracts.rst index 86cdb3c4..56d651ee 100644 --- a/docs/contracts.rst +++ b/docs/contracts.rst @@ -1328,9 +1328,9 @@ custom types without the overhead of external function calls: using BigInt for BigInt.bigint; function f() public pure { - var x = BigInt.fromUint(7); - var y = BigInt.fromUint(uint(-1)); - var z = x.add(y); + BigInt.bigint memory x = BigInt.fromUint(7); + BigInt.bigint memory y = BigInt.fromUint(uint(-1)); + BigInt.bigint memory z = x.add(y); } } diff --git a/docs/frequently-asked-questions.rst b/docs/frequently-asked-questions.rst index bb00441c..0d6fa033 100644 --- a/docs/frequently-asked-questions.rst +++ b/docs/frequently-asked-questions.rst @@ -136,14 +136,9 @@ See `struct_and_for_loop_tester.sol <https://github.com/fivedogit/solidity-baby- How do for loops work? ====================== -Very similar to JavaScript. There is one point to watch out for, though: +Very similar to JavaScript. Such as the following example: -If you use ``for (var i = 0; i < a.length; i ++) { a[i] = i; }``, then -the type of ``i`` will be inferred only from ``0``, whose type is ``uint8``. -This means that if ``a`` has more than ``255`` elements, your loop will -not terminate because ``i`` can only hold values up to ``255``. - -Better use ``for (uint i = 0; i < a.length...`` +``for (uint i = 0; i < a.length; i ++) { a[i] = i; }`` See `struct_and_for_loop_tester.sol <https://github.com/fivedogit/solidity-baby-steps/blob/master/contracts/65_struct_and_for_loop_tester.sol>`_. diff --git a/docs/miscellaneous.rst b/docs/miscellaneous.rst index 30ece7e1..d324b77a 100644 --- a/docs/miscellaneous.rst +++ b/docs/miscellaneous.rst @@ -157,7 +157,7 @@ These steps are applied to each basic block and the newly generated code is used :: - var x = 7; + uint x = 7; data[7] = 9; if (data[x] != x + 2) return 2; diff --git a/docs/security-considerations.rst b/docs/security-considerations.rst index c8d8c30b..afdecb98 100644 --- a/docs/security-considerations.rst +++ b/docs/security-considerations.rst @@ -103,7 +103,7 @@ outlined further below: mapping(address => uint) shares; /// Withdraw your share. function withdraw() public { - var share = shares[msg.sender]; + uint share = shares[msg.sender]; shares[msg.sender] = 0; msg.sender.transfer(share); } @@ -224,7 +224,6 @@ If your wallet had checked ``msg.sender`` for authorization, it would get the ad Minor Details ============= -- In ``for (var i = 0; i < arrayName.length; i++) { ... }``, the type of ``i`` will be ``uint8``, because this is the smallest type that is required to hold the value ``0``. If the array has more than 255 elements, the loop will not terminate. - Types that do not occupy the full 32 bytes might contain "dirty higher order bits". This is especially important if you access ``msg.data`` - it poses a malleability risk: You can craft transactions that call a function ``f(uint8 x)`` with a raw byte argument diff --git a/docs/types.rst b/docs/types.rst index 528807d9..e1f8e6dd 100644 --- a/docs/types.rst +++ b/docs/types.rst @@ -7,10 +7,8 @@ Types ***** Solidity is a statically typed language, which means that the type of each -variable (state and local) needs to be specified (or at least known - -see :ref:`type-deduction` below) at -compile-time. Solidity provides several elementary types which can be combined -to form complex types. +variable (state and local) needs to be specified. +Solidity provides several elementary types which can be combined to form complex types. In addition, types can interact with each other in expressions containing operators. For a quick reference of the various operators, see :ref:`order`. @@ -548,7 +546,7 @@ memory-stored reference type do not create a copy. // the data location of memoryArray is memory function f(uint[] memoryArray) public { x = memoryArray; // works, copies the whole array to storage - var y = x; // works, assigns a pointer, data location of y is storage + uint[] storage y = x; // works, assigns a pointer, data location of y is storage y[7]; // fine, returns the 8th element y.length = 2; // fine, modifies x through y delete x; // fine, clears the array, also modifies y @@ -986,26 +984,3 @@ converted to a matching size. This makes alignment and padding explicit:: bytes32(uint256(x)); // pad on the left bytes32(bytes2(x)); // pad on the right -.. index:: ! type;deduction, ! var - -.. _type-deduction: - -Type Deduction -============== - -For convenience, it is not always necessary to explicitly specify the type of a -variable, the compiler automatically infers it from the type of the first -expression that is assigned to the variable:: - - uint24 x = 0x123; - var y = x; - -Here, the type of ``y`` will be ``uint24``. Using ``var`` is not possible for function -parameters or return parameters. - -.. warning:: - The type is only deduced from the first assignment, so - the loop in the following snippet is infinite, as ``i`` will have the type - ``uint8`` and the highest value of this type is smaller than ``2000``. - ``for (var i = 0; i < 2000; i++) { ... }`` - |