web3-eth-abi

Encoding Function Calls

This feature allows you to encode function calls to be sent to the Ethereum blockchain. The code sample demonstrates how to encode a function call with a uint256 and a string parameter.

const Web3 = require('web3');
const web3 = new Web3();
const abi = require('web3-eth-abi');

const functionSignature = 'myMethod(uint256,string)';
const parameters = [123, 'Hello World'];
const encodedData = abi.encodeFunctionCall({
  name: 'myMethod',
  type: 'function',
  inputs: [{ type: 'uint256', name: 'myNumber' }, { type: 'string', name: 'myString' }]
}, parameters);

console.log(encodedData);

Decoding Function Return Values

This feature allows you to decode the return values from a smart contract function call. The code sample demonstrates how to decode a return value that includes a uint256 and a string.

const Web3 = require('web3');
const web3 = new Web3();
const abi = require('web3-eth-abi');

const encodedReturnValue = '0x000000000000000000000000000000000000000000000000000000000000007b000000000000000000000000000000000000000000000000000000000000000b48656c6c6f20576f726c64000000000000000000000000000000000000000000';
const decodedData = abi.decodeParameters(['uint256', 'string'], encodedReturnValue);

console.log(decodedData);

Encoding Event Logs

This feature allows you to encode event logs for smart contracts. The code sample demonstrates how to encode an event log with a uint256 and a string parameter.

const Web3 = require('web3');
const web3 = new Web3();
const abi = require('web3-eth-abi');

const eventSignature = 'MyEvent(uint256,string)';
const parameters = [123, 'Hello World'];
const encodedEvent = abi.encodeEventSignature({
  name: 'MyEvent',
  type: 'event',
  inputs: [{ type: 'uint256', name: 'myNumber' }, { type: 'string', name: 'myString' }]
});

console.log(encodedEvent);

Decoding Event Logs

This feature allows you to decode event logs from smart contracts. The code sample demonstrates how to decode an event log that includes a uint256 and a string.

const Web3 = require('web3');
const web3 = new Web3();
const abi = require('web3-eth-abi');

const encodedLog = '0x000000000000000000000000000000000000000000000000000000000000007b000000000000000000000000000000000000000000000000000000000000000b48656c6c6f20576f726c64000000000000000000000000000000000000000000';
const decodedLog = abi.decodeLog([
  { type: 'uint256', name: 'myNumber' },
  { type: 'string', name: 'myString' }
], encodedLog, []);

console.log(decodedLog);