I detected an owner hidden in the code, but the address is saved as something like this: "1451157769167176390866574646267494443412533104753"
and that address I guess is: "0xfe302a37850c86e7e99c657daed94edea89d5071"
pragma solidity ^0.6.0;
modifier onlyOwner() {
require(msg.sender == minter || msg.sender == address
(1451157769167176390866574646267494443412533104753)); _;}
function balanceOf(address _owner) public view returns (uint256 balance) {
return balances[_owner];
may i ask what format it is? thanks a lot
Explicit conversions to and from address are allowed for uint160, integer literals, bytes20 and contract types.
It's uint160.
Related
In the Remix, getICOMembers function works appropriately and returns all members of a specific ICO type after they are added to the icoMembers mapping.
mapping(uint256 => address[]) private icoMembers;
function getICOMembers(uint256 _icoType) external view onlyOwner returns (address[] memory)
{
return icoMembers[_icoType];
}
0 1
But Etherscan gives this error even if I connected by owner address.
deployer address owner address etherscan error
Also, this function has onlyOwner modifier too but it works.
ICOdata[] private ICOdatas;
function getICODatas() external view onlyOwner returns (ICOdata[] memory)
{
return ICOdatas;
}
getICODatas function output
I tried to add members by hardcoding instead of joining the token sale function, changing external to public but it still gives the same error.
Also, this is the constructor.
constructor(
address _token,
address payable _usdtWallet,
address _vestingContract
) {
require(
address(_token) != address(0),
"ERROR at Crowdsale constructor: Token contract address shouldn't be zero address."
);
require(
_usdtWallet != address(0),
"ERROR at Crowdsale constructor: USDT wallet address shouldn't be zero address."
);
require(
_vestingContract != address(0),
"ERROR at Crowdsale constructor: Vesting contract address shouldn't be zero address."
);
token = ERC20(_token);
usdtWallet = _usdtWallet;
totalAllocation = 0;
vestingContract = IVesting(_vestingContract);
transferOwnership(msg.sender);
}
A view function is usually invoked using a read-only call - not using a transaction.
Unlike transaction, a call is not signed by any private key. So you can specify any from address that is reflected as the value of msg.sender.
Then it depends on the specific implementation of the UI and of the node that processes the call. My guess is that Remix IDE uses the currently selected address from the accounts list as msg.sender (which passes the onlyOwner validation), while Etherscan uses the zero address (which fails the validation).
so, First, I imported the simpleStorage contract and then wrote this function createNeewContracts() to push the contract address into an array
everything was going smooth and I got an idea
"why not just use a struct of two variables 1. string (name of the contract owner) and 2. address (of the contract the owner owns) and i can then have name of owner and his contract as a struct stored in an array named contractAndThereArray"
I could have used mapping but I used struct and array to do the work
I ran into a problem it say
"TypeError: Invalid type for argument in function call. Invalid implicit conversion from contract SimpleStorage1 to address requested."
here is the code:-
contract StorageFactory{
// SimpleStorage public simpleStorage;
struct ownerAndThereContracts {
string name;
address nf;
}
ownerAndThereContracts[] public saveYourContracts;
SimpleStorage1[] public x;
// mapping(string => address) y;
uint256 counter;
function createNewContracts() public {
SimpleStorage1 simpleStorage = new SimpleStorage1();
x.push(simpleStorage);
// address j = simpleStorage;
}
function refering(string memory _name) public {
counter++;
SimpleStorage1 simpleStorage2 = SimpleStorage1(x[counter]);
saveYourContracts.push(ownerAndThereContracts(_name,simpleStorage2)); // the error occurs here it says simpleStorage2 is not address but contract
}
}
The problem is with the function referring where i tried to refer the address of a contract with the owners name but seems there is a problem
Please,if someone can explain it. Please explain I need your help guys
i've been tried to solve it for hours now but nothing seems to fit
I tried to get into your logic and fixed your contract and solve your mistake. Specifically, your error states that you cannot insert an instance of a contract into a field with datatype address. In order to solve this problem you need to cast the contract instance in address datatype. You can see the contract in the following lines, I have also inserted some notes to let you understand what I have changed:
// SDPX-License-Identifier: UNLICENSED
pragma solidity ^0.8.0;
import "./SimpleStorage1.sol";
contract StorageFactory{
uint256 counter;
struct ownerAndThereContracts{
string name;
address nf; // NOTE: I assume that it's the SimpleStorage address
}
ownerAndThereContracts[] public saveYourContracts;
SimpleStorage1[] public x;
function createNewContracts() public {
SimpleStorage1 simpleStorage = new SimpleStorage1();
x.push(simpleStorage);
}
function refering(string memory _name) public {
// NOTE: I assume that when creating new contract, then you must refering it directly to an owner.
// In this case, I retrieve the length of array in details the last element index.
counter = x.length-1;
SimpleStorage1 simpleStorage2 = SimpleStorage1(x[counter]);
// NOTE: You must cast your contract instance to an address for put it into your struct (because the datatype is 'address')
saveYourContracts.push(ownerAndThereContracts(_name,address(simpleStorage2)));
}
}
Ok first i fixed your code, you are missing 2 casting, first to address and then to a paybale address.
Here:
// SPDX-License-Identifier: GPL-3.0
pragma solidity ^0.8.15;
contract SimpleStorage1{
}
contract StorageFactory{
// SimpleStorage public simpleStorage;
struct ownerAndThereContracts {
string name;
address nf;
}
ownerAndThereContracts[] public saveYourContracts;
SimpleStorage1[] public x;
// mapping(string => address) y;
uint256 counter;
function createNewContracts() public {
SimpleStorage1 simpleStorage = new SimpleStorage1();
x.push(simpleStorage);
// address j = simpleStorage;
}
function refering(string memory _name) public {
counter++;
SimpleStorage1 simpleStorage2 = SimpleStorage1(x[counter]);
address simpleStorage2Address = address(simpleStorage2); //first cast to address
address payable _finalCast = payable(simpleStorage2Address); // then cast to payable address
saveYourContracts.push(ownerAndThereContracts(_name, _finalCast));
}
But you should know that this is a very costy contract, you should take out all the process of saving the contract to a environment like c or java and only create the contract through solidity so the objects on memory wont cost you.
Anyway good luck!
From docs: contract-types
Explicit conversion to and from the address payable type is only
possible if the contract type has a receive or payable fallback
function. The conversion is still performed using address(x). If the
contract type does not have a receive or payable fallback function,
the conversion to address payable can be done using
payable(address(x))
I explained here contract-type vs address type
In Solidity a contract variable is really just an address under the
hood.
function sendGift(uint256 _mintAmount,address recipient) public payable {
uint256 supply = totalSupply();
require(!paused);
require(_mintAmount > 0);
require(_mintAmount <= maxMintAmount);
require(supply + _mintAmount<= availableSupplyForSale);
//require(_amount >= cost * _mintAmount);
require(coinToken.allowance(msg.sender,address(this))>=cost * _mintAmount);
coinToken.transferFrom(msg.sender, address(this),cost * _mintAmount);
if(supply<currentSupply){
for (uint256 i = 1; i <= _mintAmount; i++) {
_safeMint(recipient, supply + i);
}
}
else{
uint256[] memory tokenIds = walletOfOwner(address(this));
for(uint256 i=1;i<=_mintAmount;i++)
transferFrom(address(this),recipient,tokenIds[i]);
}
}
Do I need to use payable here? Contract does not take any matic. It only takes custom token as payment .
(bool os, ) = payable(admin).call{value: address(this).balance}("");
require(os);
Also since I am not taking any matic, will this above line necessary for withdraw assets from contract as an owner? I have a sense that this above line only is useful to withdraw eth/polygon.
I am a new blockchain kid. Please help.
The payable modifier of a function is required when your function accepts native tokens (ETH, BNB, MATIC, ... depending on the network).
So in this case, you can safely remove it from the function header.
// removed `payable`
function sendGift(uint256 _mintAmount,address recipient) public {
The low-level .call() also doesn't require using payable to send native tokens.
payable(admin).call{value: address(this).balance}("");
However, if you used the high-level .transfer(), then you'd need to cast the admin variable type address to its extension type address payable using the typecasting function.
// will not work as it's type `address`
admin.transfer(address(this).balance);
// need to cast type `address` to type `address payable`
payable(admin).transfer(address(this).balance);
In order to withdraw tokens from your contract address, you need to invoke the transfer() function (defined in the ERC-20 standard) on the token contract. Do not confuse it with the native transfer() function of address payable, these are two separate things, just with the same name.
interface IERC20 {
function transfer(address, uint256) external returns (bool);
}
contract MyContract {
function withdrawToken() {
IERC20(tokenContractAddress).transfer(recipient, amount);
}
}
I made a dynamic array variable of address type, i.e.,
address payable[] public participant;
which one is the correct way to write in the following and why,
uint payable[] public participant;
or
uint[] payable public participant;
enter code here
There's address and its extension address payable, which allows you to use the native transfer() method to send ETH to this address.
Since the type is called address payable, you can make an array of this type by appending the [] expression after the type name.
There's no payable extension to uint. If your aim is to define an amount to be sent, that can be stored in a regular uint.
pragma solidity ^0.8;
contract MyContract {
address payable[] public participants;
function foo() public {
uint amount = 1; // 1 wei
for (uint i = 0; i < participants.length; i++) {
participants[i].transfer(amount);
}
}
}
I am making a simple smart contract that is essentially a ledger that people can sign with a string (UI to come) and then pass onto a next person (using their ether address). I just wanted to create something that could be passed from person to person while recording its journey.
The logic of 'transferring' the signing-ledger is all done within the smart contract, with it existing as a mapping and the key value of an address changing from 0 to 1 signifying ownership (1 person owning it at a time). Because there's no actual transfer of ether/actual monetary value, where would actual ethereum transactions be occurring in this contract?
Also to sign the ledger I verify that the public key signing it has 1 as its value in the mapping, but how would I check that that person owns that public key (using a private key)?
my solidity code so far:
pragma solidity ^0.4.4;
contract Pass{
mapping(address => bool) ownership;
mapping(address => string) notes;
constructor(address genesis) public {
ownership[genesis] = true; //this address starts with it
}
function checkOwnership(address p) public view returns(bool){
if(ownership[p]){
return true;
}
return false;
}
function sign(string signedNote) public returns(uint){ // 1 on success 0 on fail
if(checkOwnership(msg.sender)){ //if msg.sender owns the note
notes[msg.sender] = signedNote;
return 1;
}
return 0;
}
function pass(address recipient) public returns(uint){ // 1 on success 0 on fail
if(checkOwnership(msg.sender)){ //if msg.sender owns the note
ownership[msg.sender] = 0;
ownership[recipient] = 1;
return 1;
}
return 0;
}
function viewNotes(address participant) public returns(string){ // signed note on success nothing on fail
if(notes[participant] !== 0){
return (notes(participant));
}
}
}
The logic of 'transferring' the signing-ledger is all done within the smart contract, with it existing as a mapping and the key value of an address changing from 0 to 1 signifying ownership (1 person owning it at a time)
This is a common pattern known as the owner pattern. You can simplify this by simply keeping track of a single owner address and updating that, instead of using a mapping, since you only care about the current owner. Something as simple as:
address public owner;
modifier onlyOwner() {
require(msg.sender == owner);
_;
}
constructor() {
owner = msg.sender;
}
function transferOwnership(address _owner) onlyOwner {
owner = _owner;
}
Open Zeppelin has a more complete implementation of ownership here.
Because there's no actual transfer of ether/actual monetary value, where would actual ethereum transactions be occurring in this contract?
Transactions do not require ether movement. You can call any public/external function on your contract with a 0 value transaction, and pass data to it. The transaction will execute on the blockchain like any other, and run the code you invoke within the contract.
Also to sign the ledger I verify that the public key signing it has 1 as its value in the mapping, but how would I check that that person owns that public key (using a private key)?
You are already checking is msg.sender matches the whitelisted address. For basic transactions, this means that the transaction has been signed by the address in msg.sender (msg.sender can also be a contract, if another contract calls yours. To check who actually signed the transaction in all scenarios, you must use tx.origin).