Ethereum, tokens & smart contracts.

Notes on getting started Part 5. Smarter Contracts

Previous notes in case you are just joining us:
Part 1. Setting up.
Part 2. Web3.js/node. 
Part 3. Solidity.
Part 4. Smart Contracts

It feels like we are halfway up the Ethereum mountain, in this part I would like to go a bit deeper into contracts with slightly more advance features we will need later.

Constructors

A constructor (which is common in other languages) simply initializes a contract with some value,operation or set of operations, let’s say we want to store the address of the contract originator ( that’s us), we would do something like this:

FILE: constructorContract.sol
pragma solidity ^0.4.0;
contract constructorContract {
address father;
function constructorContract() {
  father = msg.sender;
 }
function whosyourfather() constant returns (address) {
      return father;
  }
}

A little extra explanation is in order:

• function constructorContract() is a our constructor function and will only run once in the life of the contract.
• We first define a new…