mapping for msg.sender doesn't seem to work

Question

state Variable is this : mapping(address=>uint) public userVotes;

now i have a function :

function votePresident(uint _id) external {
        presidents[_id-1].voteCount++;
        userVotes[msg.sender] = _id;
        Voter(msg.sender, _id, userVotes[msg.sender]);
    }

the last line is an event. So What happens here is after executing this function, I put an address of the executer in a mapping as a key and value as he passed in. Then I log it.

I have another function where I use this userVotes

function getPresident(uint _index) public view returns (uint, string, uint, string, uint) {
        President storage president = presidents[_index];
   return (president.voteCount, president.hashImage, president.id, president.name, userVotes[msg.sender] );
    }

look at the return line the last parameter, userVotes[msg.sender] . Unfonrtunatelly, it always returns 0. I don't know why it does that. I checked the log after executing the first function and I didn't see 0. i just saw the actual value. Please help . If I call the getPresident funcction in remix, it returns the actual value and not 0.

Answer 1

Anyone Might need it.

Sometimes you may forget to pass an account when you're actually calling a free method that's just returning something. In my case, I was calling a free (no-gas) function and because I didn't use the send transaction, I was forgetting to pass the account name. You can pass the account to the call function as you'd do for the send function.