第123篇 笔记-sendEther合约

How to send Ether?
You can send Ether to other contracts by

1. transfer (2300 gas, throws error)
2. send (2300 gas, returns bool)
3. call (forward all gas or set gas, returns bool)  

How to receive Ether?
A contract receiving Ether must have at least one of the functions below

1. receive() external payable
2. fallback() external payable
3. receive() is called if msg.data is empty, otherwise fallback() is called.

以下为示例合约：

// SPDX-License-Identifier: MIT
pragma solidity ^0.8.3;

contract ReceiveEther {
    /*
    Which function is called, fallback() or receive()?

                   send Ether
                       |