Questions tagged [remix]
Questions about Remix, an online browser compiler for Solidity, formerly called Browser Solidity.
0
votes
0answers
19 views
How should I pass a nested struct as a function argument in Remix IDE?
Example contract:
pragma solidity ^0.4.24;
pragma experimental ABIEncoderV2;
contract someContract {
struct structOne {
uint a;
}
struct structTwo {
uint b;
...
1
vote
1answer
14 views
Encoded input params
I created a simple test contract with a single method:
pragma solidity ^0.4.24;
contract SimpleTest {
function testFunc(string name, bool isFirst) public {
//do stuff
}
}
I'm ...
1
vote
1answer
16 views
Create Contract Solidity 0.5
My code works with compiler 0.4.25 but not with the latest version.
I want to keep track of every "Contract 2" that "Contract 1" create.
Contract 1
uint public countContract;
address[] public ...
0
votes
0answers
25 views
How dapp owners pay for their clients transcaction fees in the Ethereum Blockchain?
I am currently dealing with a problem in Ethereum Blockchain. I wrote a smart contract in Solidity Language, about a site that someone can make his Registration and after the transaction is completed ...
1
vote
1answer
17 views
Why is solidity throwing “Note: The constructor should be payable if you send value. ”, when clearly the issue is elsewhere?
I'm writing a contract on Remix that is able to deploy and track child contracts.
Here are the 2 contracts:
pragma solidity ^0.5.0;
Contract Factory
contract ContractFactory{
ChildContract[] ...
2
votes
1answer
13 views
What is the alternative to using **label** in solidity inline assembly code?
What is the alternative to using label in Solidity inline assembly code? Label is deprecated in new version.
2
votes
1answer
17 views
Invalid implicit conversion from uint256 to bytes memory requested
I am trying to create a simple random function but it gives me an error. I can't figure out what I do wrong. Solidity 0.5.0;
function random() private view returns(uint){
uint source = ...
0
votes
0answers
29 views
TypeError: Data location must be “memory” for parameter in function, but none was given
Contract fail to compile in IDE Remix.due to the following error:
TypeError: Data location must be "storage" or "memory" for parameter
in function, but none was given.
version:0.5.6+commit....
1
vote
2answers
121 views
what is the meaning of 0x0? say when variable gets assigned to it, example: keccak256(number) = 0x0;
Is 0x0 just zero? thanks
keccak256(number) = 0x0;
Or when not used as address I mean just to denote variable?
0
votes
1answer
12 views
error handling in sending custom token to multiple addresses in one transaction
i am trying to write a contract in which there is a function to divide the amount into equal parts and then deposit it into multiple accounts in one transaction. The problem is that, i want function ...
0
votes
1answer
25 views
Gas specification for function call
Is it possible to specify gas cost for a particular function call? E.g. Let's say I want a transfer() function to cost 50000000 gas, would I be able to hardcode this into the function?
0
votes
0answers
35 views
transferFrom function works but approve does not
I'm building an escrow contract and using web3js to interact with it. Currently, I am trying to approve and send an amount of custom ERC20 token from a wallet to the escrow contract. The problem is, ...
1
vote
1answer
31 views
can't call function from contract using web3.js due to gas issue
i'm really new to ethereum and solidity, so any help will be approtiat.
i'm building a smart contract and dapp using ganach and web3.js .
in my smart contract I have a function(named "add_pilot") ...
0
votes
1answer
24 views
2FA / Authentication Through Smart Contract
How can I generate something similar to 2FA on-chain? Could the private key or public key be used somehow in secrecy to compute a value or something? I need a way to authenticate a smart contract user ...
0
votes
0answers
12 views
ethereum smart cotract ioT implementation
For the preparation of a project in my thesis, I need to implement ethereum blockchain to control the access of the IoT using smart contract.
Can you recommend me a tutorial to prepare this without ...
0
votes
1answer
27 views
remix - gas limit exceeded, but contract is running on blockchain
i studying remix and ethereum, and create my local blockchain.
and create contract with remix.the contract just print simple word.
pragma solidity ^0.4.8;
contract HelloWorld{
string public ...
2
votes
1answer
18 views
Error : - browser/Mycontract.sol:29:13: Error: Undeclared identifier. assert(value % 10 == 0) ; ^----^
pragma solidity ^0.4.7 ;
contract MyContract
{
string sentence = "my first sentence" ;
address owner ;
function MyContract()
{
owner = msg.sender ;
}
function ...
0
votes
1answer
21 views
problem calling balanceOf from another contract
I try to learn solidity and i have a problem. I've created a base token and i want to call the balanceof method from this token in another contract. In Solidity Remix i get :
call to BaseTokenBet....
1
vote
1answer
32 views
Debugging a failed transaction
I have a smart contract deployed to mainnet. A user has executed a transaction that resulted in a revert failure. How can I debug this transaction to determine what exactly happened that resulted in ...
0
votes
1answer
17 views
Solidity modifier with function call error
pragma solidity >=0.4.22 <0.6.0;
contract Person {
//owner address
address private owner;
//identity
string private firstName;
string private lastName;
string private ...
1
vote
2answers
44 views
Smart Contract Working on Remix but not TestNet
This question has been asked before. however, those answers did not help me. (of course, I now can't find the "answer" atm) It said that Ropsten (what I was currently using) has fewer miners - or ...
0
votes
1answer
19 views
how to change approveAndCall() function for upgraded compiler version of solidity 0.5.1 from 0.4.6?
Here is the code snipped which is used when I'am working with compiler version 0.4.6 :
function approveAndCall(address _spender, uint256 _value, bytes memory _extraData) public returns (bool success) ...
0
votes
0answers
32 views
How does a message signed in Remix IDE?
What is signing method that is used in remix IDE and how is the hash value calculated from the message that is being signed?
0
votes
1answer
20 views
when i call balance function it shows 0 all the time ? I am deploying at remix - solidity
pragma solidity 0.4.19;
contract blackeye {
uint public max_amount = 1000000;
uint public total_balance_bought = 0;
mapping(address => uint) total_balance;
address ...
1
vote
3answers
24 views
Schedule an execution of a function in Solidity [duplicate]
I am new to solidity and to smart contracts,
i couldn't find a great resource describing how the execution of a function in the future really work behind the scenes and how to implement it.
I'd ...
0
votes
0answers
27 views
could n't find ABI constructor in my input data
I have developed the solidity code and need to verify the smart contract but I could not find Constructor Arguments ABI-encoded check the screenshots, i have developed in testnet
0
votes
1answer
44 views
NOOB Error : Transaction mined but execution failed
i´m learning Solidity now, and i saw this code on web but when i try to use the method "Deposito" i receive a error. Someone knows what's that ? (PS.: I try to put the value but every time i chose ...
0
votes
1answer
19 views
how can we set auto transfer of my tokens to the wallet which transferred me ethers
Okay so I have deployed my contract to network, and my wallet or account via which I deployed it contains all my tokens of the newly created contract. I dont want to list my token anywhere since since ...
0
votes
1answer
49 views
stack too deep , try using fewer variables
seems like i'm passing a lot of arguments in a struct creation,
this message error showed up "stack too deep , try using fewer variables"
i tried to get rid of it by using bytes32 instead of string, ...
0
votes
1answer
30 views
How to split bytes32 into multiples of 8 in solidity
I want to split bytes32 into multiples of 8 (in assembly).
I have the following code(After referring here):
function testAssembly(bytes32 _msg) public pure returns (bytes8 i, bytes8 j, bytes8 k, ...
0
votes
0answers
19 views
How to create multi forwarder address (contract)?
How to create multi forwarder address (contract)?
my code https://pastebin.com/raw/ADwPtz8q
error InternalCompilerError: Compiled contract not found.
pragma solidity 0.4.25;
contract Factory {
...
1
vote
2answers
96 views
web3.eth.Contract(abi, address) doesn't return contract instance
i'am trying to make a instance of my contract in js using web3, but when I use the function web3.eth.Contract(abi, address) the result is not the expected(I take the ABI from remix).
this is the code:...
0
votes
1answer
11 views
Error when checking the value in a mapping
I am trying to keep track of the number of bidders in my contract.
function bid() public payable an_ongoing_auction returns (bool){
uint oldval = bids[msg.sender];
require(msg.value+oldval &...
0
votes
1answer
21 views
How to set default gas limit for my custom private network?
I've connected to my custom private ethereum network in remix with web3 provider. Everything was fine, account balance, and address was retrieved successfully.
But I don't know why, but I could not ...
0
votes
1answer
17 views
ParserError: Expected primary expression
Following is my code:
pragma solidity >=0.4.17;
contract Lottery {
address public manager;
address[] public players;
constructor () public {
manager = msg.sender;
}
...
0
votes
0answers
14 views
What does endCliff and endVesting time means in PolyMath contract?
What does vesting and cliff exactly means in smart contract and blockchain terms.
Here I've added code snippet:
if (_supply == AllocationType.PRESALE) {
AVAILABLE_PRESALE_SUPPLY = ...
0
votes
1answer
23 views
Is a function prone to re-entrancy attack even if I set balance to zero within the same function (example included)
Such as in this scenario, is the hackable via re-entrancy? thanks...
function withdraw(uint256 money) public {
if(money <= balance[msg.sender]) {
(bool success, ) = msg.sender.call....
0
votes
1answer
25 views
solidity code warning in remix IDE
I am trying to create a smart contract using the but it is showing warning message in a string
"Warning: Unused function parameter. Remove or comment out the variable name to silence this warning.
...
0
votes
1answer
28 views
VM error: invalid opcode while trying to execute buy function on Remix IDE
I am using following code for custom token on ethereum.
pragma solidity >=0.4.22 <0.6.0;
contract owned {
address public owner;
constructor() public {
owner = msg.sender;
}...
0
votes
1answer
17 views
How to use 2 different constructors with open-zeppelin
I don't understand well how to implement an smart contract to create a capped Token.
If I want to follow the example of a simple token is easy:
https://github.com/OpenZeppelin/openzeppelin-solidity/...
2
votes
0answers
30 views
Why I can't use two functions with same name, but different parameters
I have a function which returns address but it gives me error if I try to read it.
I'll explain by a quick example:
Solidity:
contract TestOneReturn
{
mapping(uint => uint) m_Data;
...
1
vote
0answers
110 views
web3.eth.getAccounts() : Cannot read property 'map' of undefined
const HDWalletProvider = require('truffle-hdwallet-provider');
const Web3 = require('web3');
const provider = new HDWalletProvider( 'passphrase', 'rinkeby.infura.io/v3/mytoken' );
const web3 = new ...
0
votes
0answers
42 views
Infinite gas cost when trying to use transfer()
I tested the contract using Remix Javascript VM, Injected Web3(Ropsten) and in-built Ganache client from Embark Framework(4.0). Always getting infinite gas usage. Can someone please help me? This is ...
0
votes
0answers
27 views
Is there a way to download Remix IDE locally and access it from the Terminal (Linux)?
Is there a way to download Remix IDE locally and access it from the Terminal (Linux)?
Hi,
I think I have read that it should be possible to download Remix IDE and use it offline. In the latest ...
0
votes
1answer
37 views
Transaction pending
If I call this function the transaction get pending and never finish. Any idea?
pragma solidity ^0.4.24;
contract test
{
uint[] values = [1,2,3,4,5,6];
function removeValueFromArray(uint _num) ...
0
votes
1answer
27 views
Unable to connect to 'Web3 Provider' on Remix using http connection
I am using an http connection to connect to the Web3 Provider using Remix. The port 8454 is listening as expected.
I am getting the following error:
Not possible to connect to the Web3 provider. ...
0
votes
1answer
18 views
How to set token holder's address without duplication?
In following code I've implemented two functions to set and get Token holders.
function setTokenHolders(address _to)internal returns(bool){
for(uint i = 0; i<= tokenHolders.length; i++){
...
2
votes
0answers
24 views
How to get v,r,s parameters from transaction receipt in remix ide?
I am trying to get v,r,s parameters of a transaction so that I can use them to verify the signature.
I am not sure but I think previously remix used to give these parameters in transaction receipt.
I ...
0
votes
1answer
19 views
Gas displayed on “Remix”
Is Gas displayed on "Remix" at function execution the same as when executed on the main net?
I'm using the Javascript VM as the environment.
0
votes
2answers
24 views
Unable to fetch output from a public function in solidity
I am writing a solidity public function that changes the value of state variable and then returns it.
pragma solidity >=0.4.22 <0.6.0;
contract white_label {
uint currentId = 1;
...
