Convert Function to Function Selector
Generates the function selector (4 byte encoding) for a given function definition.
Function
Function selector (4 byte encoding)
1. What is a function selector?
The function selector is a 4 byte identifier for functions in Solidity.
2. How is the function selector calculated?
The function selector is given by turning a function into a signature, hashing the signature with keccak256
, and taking the first 4 bytes. An example and function follows below on how to derive the function selector.
function toSelector(string memory signature) internal pure returns (bytes4) {
return bytes4(keccak256(signature));
}
Reversing the operation from function selector to function is not as straight-forward. Instead, we suggest the reversal to use the Ethereum Signature Database.
3. Examples
function balanceOf(address owner)
→0x70a08231
balanceOf(address)
→0x70a08231
batch((address,address,uint256,bytes)[])
→0xc16ae7a4