在以太坊中send, transfer, call都可以进行转账操作，那么他们究竟有什么区别呢？

• transfer(2300gas，如果失败则throw)

• send(2300gas，如果失败则返回false)

• call(默认情况下将所有可用的gas传输过去，gas传输量可调，如果失败则返回false)

接收以太币的合约必须至少具有以下功能之一：

• receieve() external payable

• fallback() external payable

如果发送方的msg.data为空，那么将调用receive()，否则调用fallback()。

相同之处

1. 均是向目标地址发送以太币（以Wei为单位）

2. 发送以太币，都需要消耗固定的2300gas（gas数量少，只允许接收方合约执行最简单的操作）

不同之处

1. send执行失败会返回false，不阻碍程序的运行。transfer执行失败后会抛出异常。

// SPDX-License-Identifier: MIT
pragma solidity ^0.8.10;

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

           send Ether
               |
         msg.data is empty?
              / \
            yes  no
            /     \
receive() exists?  fallback()
         /   \
        yes   no
        /      \
    receive()   fallback()
    */

    // Function to receive Ether. msg.data must be empty
    receive() external payable {}

    // Fallback function is called when msg.data is not empty
    fallback() external payable {}

    function getBalance() public view returns (uint) {
        return address(this).balance;
    }
}

contract SendEther {
    function sendViaTransfer(address payable _to) public payable {
        // This function is no longer recommended for sending Ether.
        _to.transfer(msg.value);
    }

    function sendViaSend(address payable _to) public payable {
        // Send returns a boolean value indicating success or failure.
        // This function is not recommended for sending Ether.
        bool sent = _to.send(msg.value);
        require(sent, "Failed to send Ether");
    }

    function sendViaCall(address payable _to) public payable {
        // Call returns a boolean value indicating success or failure.
        // This is the current recommended method to use.
        (bool sent, bytes memory data) = _to.call{value: msg.value}("");
        require(sent, "Failed to send Ether");
    }
}

参考资料

Solidity by Example v 0.8.10

细究以太坊中send/transfer/call/delegatecall