const provider = new ethers.providers.JsonRpcProvider();

// Look up the current block number
await provider.getBlockNumber();
// 14135476

// Get the balance of an account (by address or ENS name, if supported by network)
final balance =
    await provider.getBalance("0x0000000000000000000000000000000000000000");
// { BigInt: "10478645750785322678769" }

// Often you need to format the output to something more user-friendly,
// such as in ether (instead of wei)
ethers.utils.formatEther(balance);
// '10478.645750785321'

// If a user enters a string in an input field, you may need
// to convert it from ether (as a string) to wei (as a BigNumber)
ethers.utils.parseEther("1.0");
// { BigInt: "1000000000000000000" }

// Create a wallet instance from a mnemonic...
final mnemonic = "announce room limb pattern dry unit scale effort smooth jazz weasel alcohol"
final walletMnemonic = Wallet.fromMnemonic(mnemonic);

// ...or from a private key
final walletPrivateKey = Wallet(walletMnemonic.privateKey);

walletMnemonic.address == walletPrivateKey.address;
// true

// The address as a Promise per the Signer API
walletMnemonic.getAddress()
// '0x71CB05EE1b1F506fF321Da3dac38f25c0c9ce6E1'

// The address as a Promise per the Signer API
walletMnemonic.address
// '0x71CB05EE1b1F506fF321Da3dac38f25c0c9ce6E1'

// The internal cryptographic components
walletMnemonic.privateKey
// '0x1da6847600b0ee25e9ad9a52abbd786dd2502fa4005dd5af9310b7cc7a3b25db'
walletMnemonic.publicKey
// '0x04b9e72dfd423bcf95b3801ac93f4392be5ff22143f9980eb78b3a860c4843bfd04829ae61cdba4b3b1978ac5fc64f5cc2f4350e35a108a9c9a92a81200a60cd64'

// The wallet mnemonic
walletMnemonic.mnemonic
// {
//   locale: 'en',
//   path: "m/44'/60'/0'/0/0",
//   phrase: 'announce room limb pattern dry unit scale effort smooth jazz weasel alcohol'
// }

// Note: A wallet created with a private key does not
//       have a mnemonic (the derivation prevents it)
walletPrivateKey.mnemonic
// null