oop - 如何在 Solidity 中实现简单的 OOP？

Question

代码：

contract A
{
    uint public foo;

    function A(uint _foo)
    {
        foo = _foo;
    }
}

contract B
{
    uint bar;

    function B()
    {
        A a = new A(42);
        bar = a.foo;
    }
}

编译错误

Test:18:15: Error: Type function () returns (uint256) is not implicitly convertible to expected type uint256.
        bar = a.foo;
              ^---^

如何读取另一个合同的公共变量？

Answer 1

contract A
{
    uint public foo;

    function A(uint _foo)
    {
        foo = _foo;
    }
}

contract B
{
    uint bar;

    function B()
    {
        A a = new A(42);
        bar = a.foo();
    }
}

bar = a.foo();而不是bar = a.foo;...