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// SPDX-License-Identifier: MIT pragma solidity >= 0.7.0 금액 mapping (address => uint) public balance; event log(bytes data); function deposit() public payable returns (uint) { balance[msg.sender] += msg.value; return msg.value; } function withdrawByCall(address payable _addr, uint _amount) public { require(balance[msg.sender] > _amount, "Insufficient Balanc..

The main difference between fallback() and receive() in Solidity is that fallback() is called when a contract receives Ether without any calldata, while receive() is called when a contract receives Ether with empty calldata. In other words, fallback() is called when a user sends Ether to a contract directly, while receive() is called when a user calls a function on a contract without passing any..

The receive() function in Solidity is a special function that is called automatically when a contract receives Ether without any calldata. This can happen when Ether is sent to the contract using the transfer() function or when a user sends Ether to the contract directly. The receive() function cannot have any arguments or return a value. It can only contain code that interacts with the contract..

The main difference between call() and delegatecall() in Solidity is that call() executes code in a new context, while delegatecall() executes code in the context of the caller. call() When you call a function using call(), the called function is executed in a new context, with its own stack and storage. This means that the called function does not have access to the caller's state, and any chan..

Delegatecall is a low-level Solidity opcode that allows a contract to execute code from another contract while using the state and storage of the calling contract. This can be used to implement a variety of features, such as: Upgrading contracts without losing data: Delegatecall can be used to upgrade a contract to a new version without losing any of the data stored in the contract. This is done..

The call() function in Solidity is a low-level function that can be used to call functions on other contracts or to send Ether to other addresses. It is a very powerful function, but it can also be dangerous if used incorrectly. The call() function takes two arguments: the address of the contract to call and the calldata to send to the function. The calldata is a byte array that contains the fun..