以太坊Solidity支持关联数组吗？

Question

例如 - 带有命名索引或哈希的数组。类似于 PHP 代码;

$array = array(
"foo" => "some foo value",
"bar" => "some bar value",);

谢谢

- Ashok Mahalik

Answer 1

Solidity支持结构体，可以从现有类型创建新类型。在函数内部可以在不同函数间传递，但还不能在合约和外部世界之间传递。

除了Jacob所说的内容，你也可以将结构体存储在映射表（哈希表）中：

mapping(address => MyStruct) structsInMap;

或者在数组中：

MyStruct[] structsInList;

这是一个小例子，它遵循与ABI兼容的固定大小规则传递值。

contract StructExample {

    struct MyStruct {
        bool isMyStruct;
        uint amount;
        address[3] addressList;
        bytes32 name;
    }

    // storage instance of MyStruct
    MyStruct myStruct;

    function StructExample(
        uint amount, 
        address address1, 
        address address2, 
        address address3,
        bytes32 name) 
    {
        myStruct.isMyStruct = true;
        myStruct.amount = amount;
        myStruct.addressList = [address1, address2, address3];
        myStruct.name = name;
    }

    function getMyStruct() 
      constant
      returns(
          bool isMyStruct,
          uint amount,
          address[3] addressList,
          bytes32 name)
    {
        return (
            myStruct.isMyStruct, 
            myStruct.amount, 
            myStruct.addressList, 
            myStruct.name);
    }
}

希望这对您有所帮助。Browser Solidity显示构造函数设置后返回的结构值。

祝一切顺利。

- Rob Hitchens

Answer 2

Solidity支持一种称为映射(mapping)的类型：

contract MappingExample {
    mapping(address => uint) public balances;

    function update(uint newBalance) {
        balances[msg.sender] = newBalance;
    }
}

http://solidity.readthedocs.io/en/develop/types.html#mappings

- Jacob