Yvette  Bell

Yvette Bell

1673212620

Ethereumjs Abi: Module Implementing The Ethereum ABI in Javascript

This library is deprecated and will not be further maintained. It specifically doesn't support the new ABI Coder v2 which is now activated by default starting with Solidity v0.8.0 released in December 2020.

We recommend to use the Ethers.js v5 ABI Encoder as a replacement which supports the new ABI Coder v2 types and is under active development.


ethereumjs-abi    

Module implementing the Ethereum ABI in Javascript. Can be used with RPC libraries for communication or with ethereumjs-vm to implement a fully fledged simulator.

Usage

Manual encoding and decoding

There are three methods of interest:

  • methodID to create a function signature
  • rawEncode to encode fields and
  • rawDecode to decode fields

Example code:

var abi = require('ethereumjs-abi')

// returns the encoded binary (as a Buffer) data to be sent
var encoded = abi.rawEncode([ "address" ], [ "0x0000000000000000000000000000000000000000" ])

// returns the decoded array of arguments
var decoded = abi.rawDecode([ "address" ], data)

Encoding and decoding aided by the JSON ABI definition

Planned for the future is supporting the JSON ABI definition:

var abi = require('ethereumjs-abi')

// need to have the ABI definition in JSON as per specification
var tokenAbi = [{"constant":true,"inputs":[{"name":"","type":"address"}],"name":"balanceOf","outputs":[{"name":"","type":"uint256"}],"type":"function"},{"constant":false,"inputs":[{"name":"_to","type":"address"},{"name":"_value","type":"uint256"}],"name":"transfer","outputs":[{"name":"success","type":"bool"}],"type":"function"},{"inputs":[],"type":"constructor"}]

var encoded = abi.encode(tokenAbi, "balanceOf(uint256 address)", [ "0x0000000000000000000000000000000000000000" ])

var decoded = abi.decode(tokenAbi, "balanceOf(uint256 address)", data)

Simple encoding and decoding

var abi = require('ethereumjs-abi')

// returns the encoded binary (as a Buffer) data to be sent
var encoded = abi.simpleEncode("balanceOf(address):(uint256)", "0x0000000000000000000000000000000000000000")

// returns the decoded array of arguments
var decoded = abi.simpleDecode("balanceOf(address):(uint256)", data)

Solidity tightly packed formats

This library also supports creating Solidity's tightly packed data constructs, which are used together with sha3, sha256 and ripemd160 to create hashes.

Solidity code:

contract HashTest {
  function testSha3() returns (bytes32) {
   address addr1 = 0x43989fb883ba8111221e89123897538475893837;
   address addr2 = 0;
   uint val = 10000;
   uint timestamp = 1448075779;

   return sha3(addr1, addr2, val, timestamp); // will return 0xc3ab5ca31a013757f26a88561f0ff5057a97dfcc33f43d6b479abc3ac2d1d595
 }
}

Creating the same hash using this library:

var abi = require('ethereumjs-abi')
var BN = require('bn.js')

abi.soliditySHA3(
    [ "address", "address", "uint", "uint" ],
    [ new BN("43989fb883ba8111221e89123897538475893837", 16), 0, 10000, 1448075779 ]
).toString('hex')

For the same data structure:

  • sha3 will return 0xc3ab5ca31a013757f26a88561f0ff5057a97dfcc33f43d6b479abc3ac2d1d595
  • sha256 will return 0x344d8cb0711672efbdfe991f35943847c1058e1ecf515ff63ad936b91fd16231
  • ripemd160 will return 0x000000000000000000000000a398cc72490f72048efa52c4e92067e8499672e7 (NOTE: it is 160bits, left padded to 256bits)

Note that ripemd160() in Solidity returns bytes20 and if you cast it to bytes32, it will be right padded with zeroes.

Using Serpent types

Serpent uses a different notation for the types, even though it will serialize to the same ABI.

We provide two helpers to convert between these notations:

  • fromSerpent: convert a Serpent notation to the ABI notation
  • toSerpent: the other way around

Example usage:

abi.fromSerpent('s')    // [ 'bytes' ]
abi.fromSerpent('i')    // [ 'int256' ]
abi.fromSerpent('a')    // [ 'int256[]' ]
abi.fromSerpent('b8')   // [ 'bytes8' ]
abi.fromSerpent('b8i')  // [ 'bytes8', 'int256' ]

abi.toSerpent([ 'bytes' ])             // 's'
abi.toSerpent([ 'int256' ])            // 'i'
abi.toSerpent([ 'int256[]' ])          // 'a'
abi.toSerpent([ 'bytes8' ])            // 'b8'
abi.toSerpent([ 'bytes8', 'int256' ])  // 'b8i'

It is to be used in conjunction with rawEncode and rawDecode:

var encoded = abi.rawEncode(abi.fromSerpent("i"), [ "0x0000000000000000000000000000000000000000" ])

var decoded = abi.rawDecode([...abi.fromSerpent("i"), ...abi.fromSerpent("i")], data)

Note: Serpent uses arbitary binary fields. If you want to store strings it is preferable to ensure it is stored as UTF8. Buffer.from(<string>, 'utf8') can be used to ensure it is properly encoded.

Contributing

I am more than happy to receive improvements. Please send me a pull request or reach out on email or twitter.

There is a lot missing, grep for FIXME in the source code to find inspiration.

EthereumJS

See our organizational documentation for an introduction to EthereumJS as well as information on current standards and best practices.

If you want to join for work or do improvements on the libraries have a look at our contribution guidelines.

License

Copyright (C) 2015 Alex Beregszaszi

Permission is hereby granted, free of charge, to any person obtaining a copy of
this software and associated documentation files (the "Software"), to deal in
the Software without restriction, including without limitation the rights to
use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of
the Software, and to permit persons to whom the Software is furnished to do so,
subject to the following conditions:

The above copyright notice and this permission notice shall be included in all
copies or substantial portions of the Software.

THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS
FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR
COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER
IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.

Download details:

Author: ethereumjs
Source code: https://github.com/ethereumjs/ethereumjs-abi

License: MIT license

#javascript #Ethereum 

What is GEEK

Buddha Community

Ethereumjs Abi: Module Implementing The Ethereum ABI in Javascript
Jack  Shaw

Jack Shaw

1672986240

A Curated List Of Awesome Ethereum Ressources

A curated list of awesome Ethereum Ressources. Inspired by awesome-go.

Contributing

Please take a quick gander at the contribution guidelines first. Thanks to all contributors; you rock!

If you see a link or project here that is no longer maintained or is not a good fit, please submit a pull request to improve this file. Thank you!


Basic {#basic}

What is Ethereum? {#what-is-ethereum}

Bitcoin 2.0? a world computer? a smart contracts platform?

Papers {#papers}

If you feel like going to the source

Roadmap {#roadmap}

  • Timeline - Expected timeline - Post from Mars 2015.
    • Olympic - 0: Olympic.
    • Frontier - 1: Frontier.
    • Homestead - 2: Homestead <----- HERE WE ARE.
    • Metropolis - 3: Metropolis - "when we finally officially release a relatively full-featured user interface for non-technical users of Ethereum"
    • Serenity - 4: Serenity - Switching the network from Proof of Work to Proof of Stake ( Casper). end of 2016?.

Branding / Logo {#branding}

Crowfunding {#crowfunding}

Remembering a time where the price of Ether was 2000 ETH per BTC

Foundation {#foundation}

The Ethereum Foundation’s mission is to promote and support research, development and education to bring decentralized protocols and tools to the world that empower developers to produce next generation decentralized applications (DAPPs), and together build a more globally accessible, more free and more trustworthy Internet.

  • Website - The Ethereum foundation Page.

Clients {#clients}

Implementations of the Ethereum protocol.

The Ethereum network {#network}

Network Stat {#network-stats}

Need information about a block, a current difficulty, the network hashrate?

  • Ethstats - See latest data of the Ethereum Network.

Blockhain Explorer {#blockchain-explorer}

Mainnet

Testnet

Ether {#ether}

Ether is the name of the currency used within Ethereum

Info {#ether-info}

SPOILER: There are about 77 million ethers in existence and every new block (an average of 15 seconds) creates 5 new ether.

Exchanges {#exchanges}

Where you can trade ethers - Remember: if you don't control the private you don't really control the ethers

Faucets {#faucets}

Free Ether? don't have big expectation :)

Mainnet

Testnet

Wallets {#wallets}

To store your ethers

  • Mist - Mist - Official wallet with integrated full node.
  • Jaxx - By KryptoKit, Wallets that unify the Bitcoin and Ethereum experience accross Devices.
  • Myetherwallet - Open Source JavaScript Client-Side Ether Wallet.
  • Icebox - Lightwallet-powered cold storage solution..

Mining {#mining}

let's make the network work! and earn some ethers!

How to {#mining-hoe-to}

Mining pools {#mining-pools}

Fell alone? join a pool

Smart Contract languages {#smart-contracts-languages}

Solidity

Solidity, the JavaScript-like language

Serpent

Serpent, the Python-like language

LLL

LLL, the Lisp-like languagee

DAPP {#dapp}

Tutorials {#tutorials}

IDE {#ide}

Others awesome things & concepts {#others}

Casper {#casper}

  • Casper - Casper - Proof of Work (PoW) for Serenity.
  • Research - ethereum/research

Whisper {#whisper}

an upcoming P2P messaging protocol that will be integrated into the EtherBrowser.

  • Whisper Wiki Wiki article about Whisper ( December 2014)-
  • Whisper ? - What is Whisper and what is it used for?.

Swarm {#swarm}

  • Swarm - Swarm for Storage .

web3-j {#web3-j}

Ethereum compatible JavaScript API which implements the Generic JSON RPC spec.

Gas {#gas}

Gas is the fundamental network cost unit and is paid for exclusively in ether.

  • Gas Doc - Gas and transaction costs from the Ethereum Documentation.
  • What is Gas? - What is the “Gas” in Ethereum? -Post from CryptoCompare.
  • Cost calculator - Calculate the cost of conducting a transaction or executing a contract on Ethereum.

Projects using Ethereum {#projects}

Big ones

  • Augur - Prediction Market.
  • Slock.it - Rent, sell or share anything - without middlemen.
  • Digix - Transparent asset tracking of LBMA GOLD with blockchain technology 2.0.

Lists of projects

Companies {#companies}

Community {#community}

Social {#social}

Skype {#skype}

Main Skype Channels

  • Ethereum - Ethereum: the main channel, bridged to IRC #ethereum.
  • Ethereum-dev - Ethereum-dev: the developer's channel, bridged to IRC #ethereum-dev.

Speciality Skype Channels

Regional Skype Channels

  • London - London General: London-based Etherians.
  • Italia - Italia: Italian Etherians.
  • Romania - Romania: Romanian Etherians.
  • Russia - Russia - Russian Etherians (Russian language).

Gitter channels

IRC channels (Freenode)

  • Go-Ethereum -
    • #ethereum: for general discussion
    • #ethereum-dev: for development specific questions and discussions
    • ##ethereum: for offtopic and banter
    • #ethereum-mining: for mining only conversations
    • #ethereum-markets: for discussions about markets

Meetups {#meetups}

Events {#events}

Devcon

Stay up to date! {#up-to-date}

Newsletter {#newsletter}

Podcast {#podcast}

Contributing

Your contributions are always welcome! Please take a look at the contribution guidelines first.

I would keep some pull requests open if I'm not sure whether the content are awesome, you could vote for them by leaving a comment that contains +1.

To be added

  • Jobs
  • Courses

Download details:

Author: lampGit
Source code: https://github.com/lampGit/awesome-ethereum

#ethereum 

Yvette  Bell

Yvette Bell

1673212620

Ethereumjs Abi: Module Implementing The Ethereum ABI in Javascript

This library is deprecated and will not be further maintained. It specifically doesn't support the new ABI Coder v2 which is now activated by default starting with Solidity v0.8.0 released in December 2020.

We recommend to use the Ethers.js v5 ABI Encoder as a replacement which supports the new ABI Coder v2 types and is under active development.


ethereumjs-abi    

Module implementing the Ethereum ABI in Javascript. Can be used with RPC libraries for communication or with ethereumjs-vm to implement a fully fledged simulator.

Usage

Manual encoding and decoding

There are three methods of interest:

  • methodID to create a function signature
  • rawEncode to encode fields and
  • rawDecode to decode fields

Example code:

var abi = require('ethereumjs-abi')

// returns the encoded binary (as a Buffer) data to be sent
var encoded = abi.rawEncode([ "address" ], [ "0x0000000000000000000000000000000000000000" ])

// returns the decoded array of arguments
var decoded = abi.rawDecode([ "address" ], data)

Encoding and decoding aided by the JSON ABI definition

Planned for the future is supporting the JSON ABI definition:

var abi = require('ethereumjs-abi')

// need to have the ABI definition in JSON as per specification
var tokenAbi = [{"constant":true,"inputs":[{"name":"","type":"address"}],"name":"balanceOf","outputs":[{"name":"","type":"uint256"}],"type":"function"},{"constant":false,"inputs":[{"name":"_to","type":"address"},{"name":"_value","type":"uint256"}],"name":"transfer","outputs":[{"name":"success","type":"bool"}],"type":"function"},{"inputs":[],"type":"constructor"}]

var encoded = abi.encode(tokenAbi, "balanceOf(uint256 address)", [ "0x0000000000000000000000000000000000000000" ])

var decoded = abi.decode(tokenAbi, "balanceOf(uint256 address)", data)

Simple encoding and decoding

var abi = require('ethereumjs-abi')

// returns the encoded binary (as a Buffer) data to be sent
var encoded = abi.simpleEncode("balanceOf(address):(uint256)", "0x0000000000000000000000000000000000000000")

// returns the decoded array of arguments
var decoded = abi.simpleDecode("balanceOf(address):(uint256)", data)

Solidity tightly packed formats

This library also supports creating Solidity's tightly packed data constructs, which are used together with sha3, sha256 and ripemd160 to create hashes.

Solidity code:

contract HashTest {
  function testSha3() returns (bytes32) {
   address addr1 = 0x43989fb883ba8111221e89123897538475893837;
   address addr2 = 0;
   uint val = 10000;
   uint timestamp = 1448075779;

   return sha3(addr1, addr2, val, timestamp); // will return 0xc3ab5ca31a013757f26a88561f0ff5057a97dfcc33f43d6b479abc3ac2d1d595
 }
}

Creating the same hash using this library:

var abi = require('ethereumjs-abi')
var BN = require('bn.js')

abi.soliditySHA3(
    [ "address", "address", "uint", "uint" ],
    [ new BN("43989fb883ba8111221e89123897538475893837", 16), 0, 10000, 1448075779 ]
).toString('hex')

For the same data structure:

  • sha3 will return 0xc3ab5ca31a013757f26a88561f0ff5057a97dfcc33f43d6b479abc3ac2d1d595
  • sha256 will return 0x344d8cb0711672efbdfe991f35943847c1058e1ecf515ff63ad936b91fd16231
  • ripemd160 will return 0x000000000000000000000000a398cc72490f72048efa52c4e92067e8499672e7 (NOTE: it is 160bits, left padded to 256bits)

Note that ripemd160() in Solidity returns bytes20 and if you cast it to bytes32, it will be right padded with zeroes.

Using Serpent types

Serpent uses a different notation for the types, even though it will serialize to the same ABI.

We provide two helpers to convert between these notations:

  • fromSerpent: convert a Serpent notation to the ABI notation
  • toSerpent: the other way around

Example usage:

abi.fromSerpent('s')    // [ 'bytes' ]
abi.fromSerpent('i')    // [ 'int256' ]
abi.fromSerpent('a')    // [ 'int256[]' ]
abi.fromSerpent('b8')   // [ 'bytes8' ]
abi.fromSerpent('b8i')  // [ 'bytes8', 'int256' ]

abi.toSerpent([ 'bytes' ])             // 's'
abi.toSerpent([ 'int256' ])            // 'i'
abi.toSerpent([ 'int256[]' ])          // 'a'
abi.toSerpent([ 'bytes8' ])            // 'b8'
abi.toSerpent([ 'bytes8', 'int256' ])  // 'b8i'

It is to be used in conjunction with rawEncode and rawDecode:

var encoded = abi.rawEncode(abi.fromSerpent("i"), [ "0x0000000000000000000000000000000000000000" ])

var decoded = abi.rawDecode([...abi.fromSerpent("i"), ...abi.fromSerpent("i")], data)

Note: Serpent uses arbitary binary fields. If you want to store strings it is preferable to ensure it is stored as UTF8. Buffer.from(<string>, 'utf8') can be used to ensure it is properly encoded.

Contributing

I am more than happy to receive improvements. Please send me a pull request or reach out on email or twitter.

There is a lot missing, grep for FIXME in the source code to find inspiration.

EthereumJS

See our organizational documentation for an introduction to EthereumJS as well as information on current standards and best practices.

If you want to join for work or do improvements on the libraries have a look at our contribution guidelines.

License

Copyright (C) 2015 Alex Beregszaszi

Permission is hereby granted, free of charge, to any person obtaining a copy of
this software and associated documentation files (the "Software"), to deal in
the Software without restriction, including without limitation the rights to
use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of
the Software, and to permit persons to whom the Software is furnished to do so,
subject to the following conditions:

The above copyright notice and this permission notice shall be included in all
copies or substantial portions of the Software.

THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS
FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR
COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER
IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.

Download details:

Author: ethereumjs
Source code: https://github.com/ethereumjs/ethereumjs-abi

License: MIT license

#javascript #Ethereum 

Rahul Jangid

1622207074

What is JavaScript - Stackfindover - Blog

Who invented JavaScript, how it works, as we have given information about Programming language in our previous article ( What is PHP ), but today we will talk about what is JavaScript, why JavaScript is used The Answers to all such questions and much other information about JavaScript, you are going to get here today. Hope this information will work for you.

Who invented JavaScript?

JavaScript language was invented by Brendan Eich in 1995. JavaScript is inspired by Java Programming Language. The first name of JavaScript was Mocha which was named by Marc Andreessen, Marc Andreessen is the founder of Netscape and in the same year Mocha was renamed LiveScript, and later in December 1995, it was renamed JavaScript which is still in trend.

What is JavaScript?

JavaScript is a client-side scripting language used with HTML (Hypertext Markup Language). JavaScript is an Interpreted / Oriented language called JS in programming language JavaScript code can be run on any normal web browser. To run the code of JavaScript, we have to enable JavaScript of Web Browser. But some web browsers already have JavaScript enabled.

Today almost all websites are using it as web technology, mind is that there is maximum scope in JavaScript in the coming time, so if you want to become a programmer, then you can be very beneficial to learn JavaScript.

JavaScript Hello World Program

In JavaScript, ‘document.write‘ is used to represent a string on a browser.

<script type="text/javascript">
	document.write("Hello World!");
</script>

How to comment JavaScript code?

  • For single line comment in JavaScript we have to use // (double slashes)
  • For multiple line comments we have to use / * – – * /
<script type="text/javascript">

//single line comment

/* document.write("Hello"); */

</script>

Advantages and Disadvantages of JavaScript

#javascript #javascript code #javascript hello world #what is javascript #who invented javascript

Ajay Kapoor

1625808587

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