Getting the length of public array variable (getter)

Question

I am trying to get the length of array from another contact. How?

contract Lottery {
    unint[] public bets;
}

contract CheckLottery {
    function CheckLottery() {
        Lottery.bets.length;
    }
}

Answer 1

You have to expose the length you want as a function return value in the source contract.

The calling contract will need the ABI and contract address, which is handled via the state var and constructor below.

pragma solidity ^0.4.8;

contract Lottery {

    uint[] public bets;

    function getBetCount()
        public 
        constant
        returns(uint betCount)
    {
        return bets.length;
    }
}

contract CheckLottery {

    Lottery l;

    function CheckLottery(address lottery) {
        l = Lottery(lottery);
    }

    function checkLottery() 
        public
        constant
        returns(uint count) 
    {
        return l.getBetCount();
    }
}

Hope it helps.