Cyfrin Updraft is an education platform specializing on teaching the next generation of smart contract developers 

Cyfrin Updraft

hi, iam new to this web3 development i started cyfrin updraft course couple of weeks ago. iam trying to follow the instructor and deploy on sepolia testnet but iam getting high gas fee of about 0.4 eth, what should i do please?

Sepolia testnet requires high gas fee

Peeranha is a decentralized questions and answers protocol for Web3 where users can organize and store their interests and skills, creating a common community platform

Peeranha Meta

Aave is a decentralized non-custodial liquidity protocol where users can participate as depositors or borrowers.

Aave

Solidity is an object-oriented, high-level language for implementing smart contracts. It is a curly-bracket language designed to target the Ethereum Virtual Machine (EVM).

Solidity

Ankr makes accessing Web3 easy for those who want to build and earn on the future web. Ankr is the main infrastructure provider for Polygon, BNB Smart Chain, and Fantom.

Ankr

Vyper is a relatively new, pythonic programming language used to write smart contracts. Vyper targets Ethereum Virtual Machine making it virtually impossible for developers to code misleading programs.

Vyper

Functionland is replacing Cloud Storage and Service Subscription economy by introducing a new category of products, called Blockchain-Attached Storage. It creates value by auto-minting crypto for the users and allocating a share to the developers.

Functionland

Fractal Visions is a builder owned and operated creative web3 NFT project hub and a multifaceted & multidimensional experience. Bridging the gap between the physical and digital world.

Fractal Visions

D_D Academy is an open-source education platform created by the Developer DAO.

D_D Academy

The Graph is a decentralized protocol for indexing and querying blockchain data. The Graph makes it possible to query data that is difficult to query directly.

The Graph

Polygon is a decentralised Ethereum scaling platform that enables developers to build scalable user-friendly dApps with low transaction fees without ever sacrificing on security.

Polygon

Web3 (also known as Web 3.0) is an idea for a new iteration of the World Wide Web which incorporates concepts such as decentralization, blockchain technologies, and token-based economics.

All Things Web3

Koii is a new way to design communications infrastructure that distributes computing authority across a wider group of personal devices.

Koii Network

Hi everyone,

I’m thrilled to share that I’m a new learner who has just completed a Solidity 101 course. The journey so far has been incredibly exciting and insightful. I’m eager to continue exploring and deepening my knowledge in Solidity and blockchain development. Looking forward to engaging with this amazing community and learning together!

I’m curious to know what resources have helped others at my level improve. Any recommendations on websites, courses, tools, or any other materials would be greatly appreciated.

Cheers,
Philip

Excited to Continue Learning Solidity!

Hello everyone , I've noticed that the offer function uses the .call{value: amount}("") method to send Ether to the recipient's address.

Could anyone provide insight into whether this function is indeed vulnerable to reentrancy and suggest any best practices or modifications to mitigate such risks?

```solidity 
function _offer(address to, uint256 amount) internal {

      balance -= amount;

      (bool success, ) = to.call{value: amount}("");
      if (!success) {
          revert TransferFailed(address(0), address(this), to, amount);
      }
  }
```

Reentrancy Vulnerability

Test Question for Cyfrin Updraft

I'm getting this error when clicking on the getBalance button of the live page of port 5500 for my anvil:

"BlockOutOfRangeError: block height is 150 but requested was 12092"

![](https://example.com/your-image.png)![](https://ipfs-cdn.peeranha.io/QmT9GJ949XC34CUGzCLAL2QyZoSXABMesC2rELvxrBZx6r)

Can anyone help explain what I missed here? Thank you!

BlockOutOfRangeError

Is it ok for me to put my private key into a `.env` file? If not, where should I put it? 

Where should I put my private key? 

I encountered an error while running the command 'forge create SimpleStorage --rpc-url http://127.0.0.1:8545 --interactive' on Windows Subsystem for Linux (WSL) with Ganache. The error message indicates a connection issue with the RPC server. I have successfully installed Ganache and switched to WSL. Are there any additional configurations or settings I need to adjust in Ganache to resolve this error? Any insights or guidance would be greatly appreciated.

error

'''Compiling...
No files changed, compilation skipped
Error:
error sending request for url (http://127.0.0.1:8545/): error trying to connect: tcp connect error: Connection refused (os error 111)'''


Forge Create Command Error with Ganache on Windows WSL

I'm trying to access a struct element within a contract instance.
In DeployFundMe.s.sol we have

address ethUsdPriceFeed = helperConfig.activeNetworkConfig();
However, in HelperConfig.s.sol we have

contract HelperConfig is Script {
    NetworkConfig public activeNetworkConfig;
    struct NetworkConfig {
        address priceFeed;
    }
    ......
}

Despite understanding that helperConfig.activeNetworkConfig is a variable of type NetworkConfig, I'm confused about why I need parentheses at the end of helperConfig.activeNetworkConfig(). I've tried alternative syntaxes without success, encountering errors like 'Member 'priceFeed' not found or not visible after argument-dependent lookup in function () view external returns (address).solidity(9582).' Can someone clarify why the correct syntax requires parentheses and provide guidance on correctly accessing struct elements in Solidity?

Confusion About Struct Elements in Solidity: Parentheses

I recently sent 0.02 ETH to the FundMe contract, which equates to a value greater than the specified minimum USD amount of 5e18. However, I am puzzled as to why the contract accepted this transaction despite it being below the minimum USD threshold.

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