SampleModifiers.sol

pragma solidity ^0.4.21;

contract SampleModifiers{
    
    address public owner;
    uint public foobar = 22;

    modifier isOwner(){
        require(owner==msg.sender);
        _;
    }
    
    // constructor
    function SampleModifiers() public {
        owner = msg.sender;     // msg.sender = address of sender.
    }

    function changeOwner(address newOwner) public {
        owner = newOwner;
    }

    function getCurrentCosts() public isOwner view returns(string){
        return "this is taken from webApi... I swear";
    }

    function getPure() public pure returns(uint){
        uint foo = 9;
        uint bar = 10;
        uint baz = foo +  bar;
        return baz;
    }

    function getView() public view returns(uint){
        uint baz = foobar + 22;
        return baz;
    }
}