Solidity is an object-oriented programming language for writing smart contracts. It is used for implementing smart contracts on various blockchain platforms, most notably, Ethereum. It was developed by Christian Reitwiessner, Alex Beregszaszi, Yoichi Hirai and several former Ethereum core contributors to enable writing smart contracts on blockchain platforms such as Ethereum.
History
Solidity was initially proposed in August 2014 by Gavin Wood; the language was later developed by the Ethereum project's Solidity team, led by Christian Reitwiessner. At present, Solidity is the primary language on Ethereum as well as on other private blockchains running on platforms that compete with Ethereum, such as Monax and its Hyperledger Burrow blockchain, which uses Tendermint for consensus. SWIFT has deployed a proof of concept using Solidity running on Burrow. A Cornell University researcher stated that Solidity was partially to blame for The DAO hack that took place in 2016. He stated: "this was actually not a flaw or exploit in the DAO contract itself: technically the Ethereum Virtual Machine was operating as intended, but Solidity was introducing security flaws into contracts that were not only missed by the community, but missed by the designers of the language themselves."
Description
Solidity is a statically-typed programming language designed for developing smart contracts that run on the EVM. Solidity is compiled to bytecode that is executable on the EVM. With Solidity, developers are able to write applications that implement self-enforcing business logic embodied in smart contracts, leaving a non-repudiable and authoritative record of transactions. Writing smart contracts in smart contract specific languages such as Solidity is claimed to be easy. As specified by Wood it is designed around the ECMAScript syntax to make it familiar for existing web developers; unlike ECMAScript it has static typing and variadic return types. Compared to other EVM-targeting languages of the time such as Serpent and Mutan, Solidity contained a number of important differences. Complex member variables for contracts including arbitrarily hierarchical mappings and structs were supported. Contracts support inheritance, including multiple inheritance with C3 linearization. An application binary interface facilitating multiple type-safe functions within a single contract was also introduced. A documentation system for specifying a user-centric description of the ramifications of a method-call was also included in the proposal, known as "Natural Language Specification". Example of a Solidity program: pragma solidity >=0.5.0 <0.7.0; contract Coin
