Blockchain became a hot topic in the last decade. Blockchain is the underlying technology enabling Bitcoin transfers. In particular, this technology ensures the integrity of digital records and enables the transfer of decentralized digital currency. After the creation of bitcoin, Vitalik Buterin saw the unexpressed potential of this technology in other fields that go beyond a simple transfer of value and created Ethereum, an open-source, decentralized blockchain with smart contract functionality. Consequently, smart contracts became the centre of the Blockchain economy. Smart contracts are programs that run on the blockchain. In the Ethereum case, the most used programming language to code smart contracts is Solidity, a relatively new programming language.