From Wikipedia, the free encyclopedia
Jump to navigation Jump to search

Solidity logo.svg
The Solidity language logo
Influenced by
JavaScript, C++, Python, PowerShell

Solidity is an object-oriented programming language for writing smart contracts.[1][2] It is used for implementing smart contracts[3][4] on various blockchain platforms, most notably, Ethereum.[5] It was developed by Gavin Wood, Christian Reitwiessner, Alex Beregszaszi, Liana Husikyan, Yoichi Hirai and several former Ethereum core contributors to enable writing smart contracts on blockchain platforms such as Ethereum.[citation needed]


Solidity was initially proposed in August 2014 by Gavin Wood;[6][non-primary source needed][7][irrelevant citation] 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.[3][non-primary source needed][8][unreliable source]

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 (EVM) 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."[9]


Solidity is a statically-typed programming language designed for developing smart contracts that run on the EVM.[10][11] 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.[12] Writing smart contracts in smart contract specific languages such as Solidity is referred to as easy (ostensibly for those who already have programming skills).[13]

As specified by Wood it is designed around the ECMAScript syntax to make it familiar for existing web developers;[citation needed] 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 (ABI) facilitating multiple type-safe functions within a single contract was also introduced (and later supported by Serpent). 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".[14][15][non-primary source needed]

Example of a Solidity program:[16][17]

contract GavCoin
  mapping(address=>uint) balances;
  uint constant totalCoins = 100000000000;

  /// Endows creator of contract with 100B GAV. 100x10^9 = 100B
  function GavCoin(){
      balances[msg.sender] = totalCoins;

  /// Send $((valueInmGAV / 1000).fixed(0,3)) GAV from the account of $(message.caller.address()), to an account accessible only by $(to.address()).
  function send(address to, uint256 valueInmGAV) {
    if (balances[msg.sender] >= valueInmGAV) {
      balances[to] += valueInmGAV;
      balances[msg.sender] -= valueInmGAV;

  /// getter function for the balance
  function balance(address who) constant returns (uint256 balanceInmGAV) {
    balanceInmGAV = balances[who];


Development platform availability[edit]

Blockchain platforms[edit]

Solidity is available on:


  1. ^ Allison, Ian (12 August 2016). "PwC blockchain expert pinpoints sources of ambiguity in smart contracts". IBTimes (News). Retrieved 14 December 2016.
  2. ^ Afshar, Vala; Evangelist, ContributorChief Digital; Salesforce (17 July 2017). "Ethereum Is The Second Most Valuable Digital Currency, Behind Bitcoin". HuffPost. Retrieved 10 April 2019.
  3. ^ a b "SOFE Berlin: Swift unveils blockchain proof-of-concept". Finextra (News). 24 November 2016. Retrieved 24 November 2016.
  4. ^ Black, David B. "Blockchain Smart Contracts Aren't Smart And Aren't Contracts". Forbes. Retrieved 10 April 2019.
  5. ^ Petersson, David. "How Smart Contracts Started And Where They Are Heading". Forbes. Retrieved 10 April 2019.
  6. ^ Benoit Schweblin. "StackEdit Viewer".
  7. ^ a b "Blockchain and big data worth watching in the coming year". Business. International Business Times. 20 December 2016. Retrieved 28 September 2017.
  8. ^ KENTOURIS, CHRIS (13 December 2016). "Blockchain's Smart Contracts: What's Smart, What's Not". Finops (News). Retrieved 14 December 2016.
  9. ^ Finley, Klint (18 June 2016). "A $50 MILLION HACK JUST SHOWED THAT THE DAO WAS ALL TOO HUMAN". Wired (News). Retrieved 18 February 2017.
  10. ^ "Hyperledger Fabric Tutorial - Create a blockchain app for loyalty points". IBM Developer. Retrieved 10 April 2019.
  11. ^ a b Allison, Ian (30 March 2016). "Microsoft adds Ethereum language Solidity to Visual Studio". International Business Times. Retrieved 11 May 2016.
  12. ^ Allison, Ian (30 March 2016). "Microsoft adds Ethereum language Solidity to Visual Studio". International Business Times. Retrieved 11 May 2016.
  13. ^ Mougayar, William (26 April 2016). The Business Blockchain: Promise, Practice, and Application of the Next Internet Technology. Wiley Publishing. p. 58. ISBN 978-1119300311.
  14. ^ Kapetanios-2008-06-27 & p.309.
  15. ^ ethereum. "Ethereum Natural Specification Format". GitHub.
  16. ^ RJ Catalano, one of the core developers, see VoR0220 on github
  17. ^ a b Schneier, Karthikeyan; Schneier, Antoine; Bhargavan, Cedric; Delignat-Lavaud, Anitha; Fournet, Gollamudi; Schneier, Bruce; Rastogi, Nadim; Sibut-Pinote, Aseem; Rastogi1, Thomas; Swamy, Nikhil; Zanella-Beguelin, Santiago (27 August 2016). "Short Paper: Formal Verification of Smart Contracts" (PDF). Microsoft Research, French Institute for Research in Computer Science and Automation, Harvard University. Archived (PDF) from the original on 23 August 2017.

External links[edit]