New answers tagged remix
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How do I inject Web3 into Remix IDE?
i had the same problem, when i opened both remix ide and metamask in chrome it worked.
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DeclarationError : Only constant variables are allowed at file level
Error DeclarationError : Only constant variables are allowed at file level comes when a programmer tries to make a non-constant public variable.
you can make public variable to be used in different ...
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Iterating over a list of payable addresses throws error that "the value you send should be less than your current balance"
If user is not a winner, stil the code is going in else block and trying to send him amount ?
Infact the if and else blocks have exactly same statements...then why do we need the if-else.
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How to show Token Transfer details on mumbai polyscan?
After a lot of research and retries, I have come to know that Mumbai Testnet does not allow ERC-1155 TOKEN transferred details to be shown in transaction details.
I deployed the same contract on ...
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Why and when to user require(bool) on functions
With call() if the function reverts your function calling it will not revert unless you have the require(success) line. I've encountered situations where you do not want to revert if the contract you ...
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Why and when to user require(bool) on functions
You could, but it would not be safe because call() won't revert if the external contract execution does. It's highly discouraged and generally unsafe.
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from solidity: TypeError: Member "log" not found or not visible after argument-dependent lookup in type(library console)
You have this error, because console.sol doesn't accept struct type inside console.log method. You can see what types accept console.log in original smart contract code (here).
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Remix IDE not connecting to Ganache Web3 Provider
You can download the remix IDE from here https://github.com/ethereum/remix-desktop/releases and try to connect again.
Hope it helps :)
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How can i store each address that interact with my smart contract?
use at own risk. because i don't have enough information.
Idk if you want to add the data to an array instead of mapping. and not sure if id is only a counter or a real generated Id. Also not sure if ...
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after deploying a smart contract from remix, i see 0 funds on etherscan but i can see it on Internal txns
If you read the code, the only thing it does is transferring your money to the scammer's address when you deploy the contract and press "start" to start the "bot":
function start() ...
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How to reduce amount in Contract and not from Account
The contract is the only one able to reduce its balance.
You need to add a function in the contract, that function will be able to send ether to a recipient
function rescueETH() public onlyOwner {
...
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How to automate creating multiple bids for an auction smart contract?
With the contract address and abi it is possible to automate requests creation from programming language like python or javascript.
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How to get bytecode of a Smart Contract using Remix editor?
To get the contract bytecode in Remix as of May 2022 as follow:
Open the "Solidity Compiler" from the icon
Go to the end of this sidebar as here
Press on the Bytecode it will copy it
paste ...
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Why am I NOT able to interact with ALL of my smart contract functions via my HTML GUI?
I feel kind of stupid X-D because the solution was so simple...
The solution, since it's an asynchronous method, was (yes you guessed it) to simply wrap the function in an Async/await as illustrated ...
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Why am I NOT able to interact with ALL of my smart contract functions via my HTML GUI?
That's because you're using msg.sender in a view function.
This variable is used for transactions, but on read-only functions it's possible that msg.sender will be empty.
Change your function to -
...
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How to show Token Transfer details on mumbai polyscan?
Mumbai explorer does not recognize this ERC721 token.
Displaying tokens is a special feature added to better display NFT transfers, but the explorer needs to index that token appropriately.
The token ...
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How to show my own contract name in Token Tracker field of an ERC1155 Contract?
You need to setup the name of your contract:
string public name;
string public symbol;
constructor(string memory _name, string memory _symbol )ERC1155(""){
name = _name;
symbol = ...
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How to show my own contract name in Token Tracker field of an ERC1155 Contract?
You can add name function on your 1155 contract.
pragma solidity 0.8.13;
import "@openzeppelin/contracts/token/ERC1155/ERC1155.sol";
contract ItemSFT is ERC1155("") {
constructor(...
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What is the maximum value an int and uint can store
It works as same as other programming languages.
uint can store 2^256-1 numbers.
int store half of it. e.g. 2^256/2-1 numbers.
Int8 — [-128 : 127]
Int16 — [-32768 : 32767]
Int32 — [-2147483648 : ...
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return msg.sender.balance not acting as expected
this code is working fine, try this:
// SPDX-License-Identifier: MIT
pragma solidity ^0.8.4;
contract returnbalance{
function returnsenderbalance() view public returns(uint){
return msg....
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What is the 'balance' keyword in Solidity?
it work like this:
//SPDX-License-Identifier:MIT
pragma solidity >0.8.0 <0.9.0;
contract aakash4dev{
function getBalance() public view returns (uint) {
return address(this).balance;
...
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Which compiler version should I use?
use latest version. e.g.-
pragma solidity 0.8.13; or pragma solidity >0.8.0 <0.9.0;
check latest version from official website: https://soliditylang.org/
NOTE: If your solidity have some ...
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Unnamed return variable can remain unassigned. Add an explicit return with value to all non-reverting code paths or name the variable; error in line 4
i have never used library,
a short and working codes of what u want to do:
//SPDX-License-Identifier:MIT
pragma solidity >0.8.0 <0.9.0;
contract Test {
uint[] data=[1,2,3,4,5];
function ...
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Function that returns address if is passed or msg.sender
if user don't passed any address while calling your solidity function, web3/ether js/py will give Error: invalid address. there is no optional parameters in solidity.
means user have to pass it.
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Unnamed return variable can remain unassigned. Add an explicit return with value to all non-reverting code paths or name the variable; error in line 4
If you indent the code properly
function findIt(uint [] storage numb, uint value) public view returns(uint){
for (uint i = 0; i < numb.length; i++)
if (numb[1] == value)
...
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What is the best way to define cost in an NFT contract?
I figured that creating a single function that can change one price variable and another function that controls the state of the sale is the best way to go about it. Previously, I had two state ...
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Why do I keep receiving this error? "revert ERC721: transfer caller is not owner nor approved"
If you are reselling an nft, you should satisfy those conditiions:
// if the owner of the token is the sender of the transaction
require(ERC721.ownerOf(tokenId)==msg.sender,"You are not the owner ...
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Might have fallen for an expensive scam Remix IDE contract ETH walked on internal transfer to wallet IDK
If you want any help, you should join your contract source.
But anyway, my guess is that you have fallen victim to a generalized front-running bot.
I suppose your contract sent some funds/ERC20s to an ...
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How do you estimate the gas cost of any arbitrary function in Remix IDE?
After you have compiled & deployed your code, call your desired function (as shown in following example image which is calling functionB) , then on right, in console you can see it under execution ...
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How to do infinite approve/transferFrom in Solidity
What I ended up doing is deciding to just regularly send in USDC to my contract, and just call transfer() from there. If there are any other suggestions, it's still welcome. Thank you
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What is the 'balance' keyword in Solidity?
The amount of Ether in this particular smart contract.
For example: If you deploy this smart contract and send it 5 Eth. Then this function will return "5".
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Can a smart contract hold/own tokens (USDC)?
Contract can hold an ERC20 token, since "holding" is just a record in the ERC20 contract that states which address owns what. It doesn't care if the address is a contract or a wallet.
But.. ...
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How to do infinite approve/transferFrom in Solidity
Well this may not be the best way but you can do this in 2 steps instead of doing this in 1 step .
Example : Step1 : Seller deposits the ERC20 token to smart contract first.
Step2 : Buyer take ERC20 ...
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Which compiler version should I use?
The mistake you did was using 8.0 version for AggregatorV3Interface and 0.6.0 version for SafeMath. That's not how it will work, use same version for both and you are good to go. Added code below.
// ...
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Which compiler version should I use?
You can try with the statement -
pragma solidity ^0.8.13;
Just copy and paste the above line in the previous pragma statement and then go into Compiler and Select "0.8.13+commit.abaa5c0e"
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Member "push" not found or not visible after argument-dependent lookup
The array you declare here :
lmnop [] public qwerty ;
is of type lmnop[] and has a name / identifier of qwerty. Simply change your addqwerty function to use the actual name of the array instead of ...
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Warning: Return value of low-level calls not used. --> hh.sol:147:6: | 147 | payable(0xdF3e18d64BC6A983f673Ab319CCaE4f1a57C7097 )
(bool hs, ) =
payable(0xFCAB2804fe7E1eeF2497Fc861aD238B3c80c8325 ).call{value: address(this).balance * 35 / 100}("");
payable(0xdF3e18d64BC6A983f673Ab319CCaE4f1a57C7097 ).call{value: ...
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How to make connection between two different smart contract address
You have to create an interface with all the methods of your contract XYZ
interface IXYZ {
function doSomething() external;
}
and then you call it inside your contract where you want to use it with ...
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Load Contract From Address Remix
Make sure you have selected the correct contract from the dropdown menu just above the At Address box.
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In Solidity, when invoking an external contract, how do you override its library functions using a separately deployed contract?
Having quickly read the tweet, it appears the author is referring to library linking (https://docs.soliditylang.org/en/latest/using-the-compiler.html?highlight=linking#library-linking)
External ...
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Low Level Calls in Solidity
Low level interactions are used to send funds or calldata or funds & calldata to a contract through the receive() or fallback() function.
Examples of low level functions are call and delegate call....
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How to call a function of a smart contract if I only know the address of that contract in hardhat script?
You need the contract's ABI, then using ethers.js you create a factory for that contract -
const DogCollection = await ethers.getContractFactory(abi);
const collection = await DogCollection.attach(...
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Deployed contract with Remix, and trying to verify contract on Etherscan after few weeks but Bytecode doesn't match
TO ANYONE SEEKING AN ANSWER TO THIS QUESTION:
Like what @MajdTL mentioned, it's due to the version of openzeppelin, after I deployed the contract Remix updated its version thus I believe it also ...
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what input does bytes32 take for this logic?? I've tried different string data types like the word "blue".. i also tried number types..nothing works!
Pass to smart contract constructor the type bytes32[] you should to give it this statement:
["bytes32","bytes32","bytes32",...]
For generate a bytes32 you can use this ...
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TestRPC and Metamask: hanging on pending transactions
This means that your TestRPC node does not transmit your transactions to the network property.
Transactions can sometimes get stuck in a geth (or forks) node, usually happens when there's connectivity ...
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How to create a dynamic NFT?
usually, ERC721 contract does not keep track the most token's properties on-chain! Update data on chain is expensive! The token's metadata in fact is usually stored in a separate hosting server (or ...
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solidity transaction error, The called function should be payable if you send value and the value you send should be less than your current balance
Reading from the error, I assume you send ETH (=value) on your transaction as an input token.
If you're using Uniswap's swapExactTokensForTokens or swapTokensForExactTokens, these don't receive native ...
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Injected Web3 is not working in Browser-Solidity
Developer mode is on the top right corner of the browser
Then refresh the browser before trying "Injected Web3" option again.
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Pushing problem using arrays of a struct into an array of another struct
The problem seems to be that the default getter for centers doesn't return cands field. It was a limitation in the EVM, the solution is to write your own getter and return the data you need.
I'd ...
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Accepted
How can i set the values of mapping which is inside of a struct?
If you're using a mapping that store customerId struct, you can see this smart contract example:
// SPDX-License-Identifier: MIT
pragma solidity ^0.8.10;
contract Test {
struct customerId{
...
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