how can get getSighash in v6

[Cazs03]

In previous version i can get signature from this method

const iface = new ethers.utils.Interface(abi)
const selector = iface.getSighash('transfer')

How can do it in new version?

[ardislu]

Get the FunctionFragment object from the interface using getFunction, then call the selector property. Example:

const abi = [
  'function balanceOf(address _owner) external view returns (uint256 balance)',
  'function transferFrom(address _from, address _to, uint256 _value) external returns (bool success)',
  'function approve(address _spender, uint256 _value) external returns (bool success)',
  'function allowance(address _owner, address _spender) external view returns (uint256 remaining)'
];
const interface = new ethers.Interface(abi);

interface.getFunction('balanceOf').selector;
// '0x70a08231'

interface.getFunction('transferFrom').selector;
// '0x23b872dd'

You can also directly calculate the keccak256 hash from a string using the id function and get the first 4 bytes:

ethers.id('balanceOf(address)').substring(0, 10);
// '0x70a08231'

ethers.id('transferFrom(address,address,uint256)').substring(0, 10);
// '0x23b872dd'

[ricmoo]

Exactly the preferred way; using the FunctionFragment object itself. :)