如何在固体中实现简单的OOP

Question

Code：

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;
              ^---^

如何在另一个合约中读取合约的公共变量？

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;...