Web3.js 1.0.0 Documentation: Interacting with Ethereum Using `web3-eth`

The web3-eth package enables seamless interaction with the Ethereum blockchain and smart contracts. Below is a comprehensive guide to its functionalities, optimized for clarity and search intent.

Introduction to web3-eth

The web3-eth package is a core component of Web3.js, designed to facilitate Ethereum blockchain interactions. It supports:

• Querying blockchain data
• Sending transactions
• Deploying and interacting with smart contracts

Basic Setup

// Importing the Eth package
var Eth = require('web3-eth');
var eth = new Eth(Eth.givenProvider || 'ws://some.local-or-remote.node:8546');

// Using the umbrella Web3 package
var Web3 = require('web3');
var web3 = new Web3(Web3.givenProvider || 'ws://some.local-or-remote.node:8546');
// Access via web3.eth

Key Features

1. Checksum Addresses

All Ethereum addresses returned by web3-eth are checksummed (mixed uppercase/lowercase) to ensure validity. Invalid checksums trigger errors.

Example

web3.eth.getAccounts(console.log);
> ["0x11f4d0A3c12e86B4b5F39B213F7E19D048276DAe", "0x85F43D8a49eeB85d32Cf465507DD71d507100C1d"]

2. Provider Management

Configure providers for modules like web3.eth, web3.shh, and web3.bzz.

Methods

• setProvider(myProvider): Updates the provider for a module.
• providers: Lists available providers (HTTP, Websocket, IPC).

Example: Local Geth Node

var web3 = new Web3('http://localhost:8545');
web3.setProvider(new Web3.providers.WebsocketProvider('ws://localhost:8546'));

3. Transaction Handling

Methods

• sendTransaction(): Broadcasts transactions.
• signTransaction(): Signs transactions offline.
• getTransactionReceipt(): Retrieves transaction details.

Example

web3.eth.sendTransaction({
  from: '0x...',
  to: '0x...',
  value: '1000000000000000000'
}).then(console.log);

4. Blockchain Queries

Methods

• getBlock(): Fetches block data.
• getBalance(): Checks an address balance.
• getCode(): Retrieves contract bytecode.

Example

web3.eth.getBalance("0x...").then(console.log);
> "1000000000000000000"

FAQs

1. How do I handle checksum addresses?

Checksum addresses are auto-validated. Use .toLowerCase() to bypass checksums if needed.

2. What providers are supported?

• HTTP
• Websocket
• IPC (Node.js only)

👉 Explore Ethereum development tools

3. How do I estimate gas costs?

Use estimateGas() with a transaction object:

web3.eth.estimateGas({to: "0x...", data: "0x..."}).then(console.log);

Conclusion

web3-eth simplifies Ethereum interactions with robust methods for queries, transactions, and contract management. For advanced use, refer to the official Web3.js docs.

👉 Start building on Ethereum today

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