when writing a simple voting smart contract, it gives an error :

Question

//SPDX-Licence-Identifier: GNU AGPL
pragma solidity >= 0.5.0 < 0.9.0;

contract Election{
    struct Candidate{
        string name;
        uint numVotes;
}
    struct Voter{
        string name;
        bool authorised;
        uint whom;
        bool voted;

    }

    address public owner;
    string public electionName;
    
    mapping (address => Voter) public voters;
    Candidate [] public candidates;
    uint public totalVotes;

    modifier ownerOnly(){
        require(msg.sender == owner);
        _;
    }

    function startElection(string memory _electionName) public{
        owner = msg.sender;
        electionName = _electionName;
    }

    function addCandidate(string memory _candidateName) ownerOnly public{
        candidates.push(Candidate(_candidateName, 0));

    }

    function authorizeVoter(address _voterAdress) ownerOnly public{
        voters[_voterAdress] authorised = true;
    }

    function getNumCandidates() public view return(uint){
        return candidates.length;
    }

    function vote(uint candidateIndex) public{
        require(!voters[msg.sender].voted);
        require(voters[msg.sender].authorised);
        voters[msg.sender].whom = candidateIndex;
    }
 
}//SPDX-Licence-Identifier: GNU AGPL
pragma solidity >= 0.5.0 < 0.9.0;

contract Election{
    struct Candidate{
        string name;
        uint numVotes;
}
    struct Voter{
        string name;
        bool authorised;
        uint whom;
        bool voted;

    }

    address public owner;
    string public electionName;
    
    mapping (address => Voter) public voters;
    Candidate [] public candidates;
    uint public totalVotes;

    modifier ownerOnly(){
        require(msg.sender == owner);
        _;
    }

    function startElection(string memory _electionName) public{
        owner = msg.sender;
        electionName = _electionName;
    }

    function addCandidate(string memory _candidateName) ownerOnly public{
        candidates.push(Candidate(_candidateName, 0));

    }

    function authorizeVoter(address _voterAdress) ownerOnly public{
        voters[_voterAdress] authorised = true;
    }

    function getNumCandidates() public view return(uint){
        return candidates.length;
    }

    function vote(uint candidateIndex) public{
        require(!voters[msg.sender].voted);
        require(voters[msg.sender].authorised);
        voters[msg.sender].whom = candidateIndex;
    }
 
}//SPDX-Licence-Identifier: GNU AGPL
pragma solidity >= 0.5.0 < 0.9.0;

contract Election{
    struct Candidate{
        string name;
        uint numVotes;
}
    struct Voter{
        string name;
        bool authorised;
        uint whom;
        bool voted;

    }

    address public owner;
    string public electionName;
    
    mapping (address => Voter) public voters;
    Candidate [] public candidates;
    uint public totalVotes;

    modifier ownerOnly(){
        require(msg.sender == owner);
        _;
    }

    function startElection(string memory _electionName) public{
        owner = msg.sender;
        electionName = _electionName;
    }

    function addCandidate(string memory _candidateName) ownerOnly public{
        candidates.push(Candidate(_candidateName, 0));

    }

    function authorizeVoter(address _voterAdress) ownerOnly public{
        voters[_voterAdress] authorised = true;
    }

    function getNumCandidates() public view return(uint){
        return candidates.length;
    }

    function vote(uint candidateIndex) public{
        require(!voters[msg.sender].voted);
        require(voters[msg.sender].authorised);
        voters[msg.sender].whom = candidateIndex;
    }
 
}

error text :Election.sol:43:45: ParserError: Expected '{' but got 'return' function getNumCandidates() public view return(uint){ ^----^

Answer 1

Simple syntax error. You are using the wrong type of brackets to define a struct

Instead of what you currently have :

struct Candidate (
  string name;
  uint numVoters;
)

Change it to this :

struct Candidate {
  string name;
  uint numVoters;
}

Answer 2

Your function is using wrong word for return keywords in the function.

Instead of looking like this.

function getNumCandidates() public view return(uint){
        return candidates.length;
    }

It should be written like this.

function getNumCandidates() public view returns(uint){
    return candidates.length;
}