sepisoltani

contract NumberInterface {
  function getNum(address _myAddress) public view returns (uint);
}

sepisoltani

contract Sandwich {
  uint private sandwichesEaten = 0;

  function eat() internal {
    sandwichesEaten++;
  }
}

contract BLT is Sandwich {
  uint private baconSandwichesEaten = 0;

sepisoltani

import "./someothercontract.sol";

contract newContract is SomeOtherContract {

}

sepisoltani

contract Animal {
  function walk() public returns (string memory) {
    return "walking";
  }
}

contract Cat is Animal {
  function run() public returns (string memory) {
    return "running";
  }

sepisoltani

contract Example{

function sayHiToVitalik(string memory _name) public returns (string memory) {
  // Compares if _name equals "Vitalik". Throws an error and exits if not true.
  // (Side note: Solidity doesn't have native string comparison, so we
  // compare their keccak256 hashes to see if the strings are equal)
  require(keccak256(abi.encodePacked(_name)) == keccak256(abi.encodePacked("Vitalik")));
  // If it's true, proceed with the function:
  return "Hi!";
}

sepisoltani

contract Example{

mapping (address => uint) favoriteNumber;

function setMyNumber(uint _myNumber) public {
  // Update our `favoriteNumber` mapping to store `_myNumber` under `msg.sender`
  favoriteNumber[msg.sender] = _myNumber;
  // ^ The syntax for storing data in a mapping is just like with arrays
}

sepisoltani

contract Example{

// For a financial app, storing a uint that holds the user's account balance:
mapping (address => uint) public accountBalance;

}

sepisoltani

YourContract.IntegersAdded(function(error, result) {

  alert("event fired")
  
})

sepisoltani

contract Example{

// declare the event
event IntegersAdded(uint x, uint y, uint result);

function add(uint _x, uint _y) public returns (uint) {
  uint result = _x + _y;
  // fire an event to let the app know the function was called:
  emit IntegersAdded(_x, _y, result);
  return result;

sepisoltani

contract Example{

uint8 a = 5;
uint b = 6;
// throws an error because a * b returns a uint, not uint8:
uint8 c = a * b;
// we have to typecast b as a uint8 to make it work:
uint8 c = a * uint8(b);