I have a method :

function getBalance(address _add) public view 
            returns (uint256, string memory, bool, uint256, uint256, uint256) {

I have tried many ways to get some hash which will work for my json rpc. But I am not able to get through. Tried combinations which didn't work :

web3.sha3('getBalance(address) returns (uint256, string,bool,uint256,uint256,uint256)'); "0x2560a3f9b1f28442f55de402532d55bffa0794ee53310ed4dc65d3dda6a8fc4b"

web3.sha3('getBalance(address) returns (uint256, string memory,bool,uint256,uint256,uint256)'); "0x963fc1d2d6f67d205b9f56340f6f9853ea45969dcc25182fbd9705abe74cfcbf"

web3.sha3('getBalance(address) view returns (uint256, string memory,bool,uint256,uint256,uint256)'); "0xdcd78e55620fe9302439c2ccb0c23d69f7399b61e3b0b6c9c15142f85fe6b3fa"

web3.sha3('getBalance(address) view returns (uint256,string,bool,uint256,uint256,uint256)'); "0x97abd19f4ac051fb6b277f2c947801a9120e0935a7225ff322d1cf2a2dcb1b8a"

web3.sha3('getBalance(address) view returns (uint256,string memory,bool,uint256,uint256,uint256)'); "0xc174d458674c0f18ffbf8addc06d41eb80a9bcab82d31fee290be4368339840e"

web3.sha3('getBalance(address) returns (uint256,string,bool,uint256,uint256,uint256)'); "0x02cd8e0e733ce057edefbb512190a6e6ecdae93ea96aa413d83cc7ad5c3d312c"

web3.sha3('getBalance(address) returns (uint256,string memory,bool,uint256,uint256,uint256)'); "0x48a0f2e06a2c0c3b033efbad3ecde8042792381edf9c600c2d1f7fb35a43c986"

web3.sha3('getBalance(address)'); "0xf8b2cb4f3943230388faeee074f1503714bff212640051caba01411868d14ae3"

Can someone please help.

  • The last one is correct: web3.sha3('getBalance(address)'). You'll want just the first four bytes (0xf8b2cb4f). If you're having trouble using that, please share the code / HTTP request you're making that uses that function selector. – user19510 May 6 at 16:33
  • @smarx That is not working for me. This is the request : {"jsonrpc":"2.0", "method":"eth_call", "params":[{"from": "eth.accounts[0]", "to": "0x9d13c6d3afe1721beef56b55d303b09e021e27ab", "data": "0xf8b2cb4f000000000000000000000000ed9d02e382b34818e88b88a309c7fe71e65f419d", "gas":4700000}],"latest", "id":1} – Tarun May 7 at 6:43
  • Response am getting is : <error> <code>-32602</code> <message>invalid argument 0: json: cannot unmarshal hex string without 0x prefix into Go struct field CallArgs.from of type common.Address</message> </error> If I use this from geth console, I get something which seems correct : var result = web3.eth.call({ to: "0x9d13c6d3afe1721beef56b55d303b09e021e27ab", data: "0xf8b2cb4f000000000000000000000000ed9d02e382b34818e88b88a309c7fe71e65f419d" }); – Tarun May 7 at 6:49
  • It looks like you're sending the quoted string "eth.accounts[0]" in the RPC request instead of the actual address. – user19510 May 7 at 9:46
  • @smarx yeah, you are right. that changed the error to : <message>invalid character 'e' looking for beginning of value</message> Seems now something wrong in data. – Tarun May 7 at 14:52

The return type of a function is not part of this signature.

See here for more details (specifically, take a look at the note).

If you want to encode your function, then you can try this (web3.js v1.x):

function encode(abiArray, functionName, functionArgs) {
    for (const object of abiArray)
        if (object.name == functionName)
            return web3.eth.abi.encodeFunctionCall(object, functionArgs);
    throw new Error("function " + functionName + " does not exist");

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