Created using remix-ide: Realtime Ethereum Contract Compiler and Runtime. Load this file by pasting this gists URL or ID at https://remix.ethereum.org/#version=soljson-v0.5.6+commit.b259423e.js&optimize=false&runs=200&gist=

contracts...Practice.sol

//Klaytn IDE uses solidity 0.4.24 0.5.6 versions.
pragma solidity >=0.4.24 <=0.5.6;

contract Practice {
    uint256 private totalSupply = 10;
    string public name = "KlayLion";
    address public owner; // contract deployer
    mapping(uint256 => string) public tokenURIs; // key - value type declare

    // mint(tokenId, uri, owner) : 발행
    // transferFrom(from, to, tokenId) : 전송
    constructor () public {
        owner = msg.sender; // 생성자는 conract 배포 시 실행, 배포자의 주소를 owner에 저장
    }

    function getTotalSupply() public view returns (uint256) {
        return totalSupply + 1000000;
    }

    function setTotalSupply(uint256 newSupply) public {
        require(owner == msg.sender, 'Not owner'); // msg.sender가 owner랑 같을 때만 다음 줄 실행, 그렇지 않으면 err msg 띄움
        totalSupply = newSupply;
    }

    function setTokenUri(uint256 id, string memory uri) public { // memory는 좀 긴 타입의 데이터를 표시할 떄 쓴다. 
        tokenURIs[id] = uri; // mapping
    }
}