简介特色
Web 3.0
详细内容
想要了解Web3.0,{I88公链-I928合约-开发8024},首先我们要明白Web1.0和Web2.0是什么。所谓的Web其实就是互联网的意思,但是随着时代的发展,互联网也变得越来越不一样,所以我们就给互联网的每个重大阶段分别取名,分为Web1.0、Web2.0和Web3.0。
The Ethereum network processes transactions in blocks with new blocks getting confirmed around every 17 seconds.The miners look at transactions they have received and select which transactions to include in a block,based who has paid a high enough gas price to be included.Additionally,when transactions are sent to the Ethereum network they are forwarded to each node for processing.Thus,a person who is running an Ethereum node can tell which transactions are going to occur before they are finalized.A race condition vulnerability occurs when code depends on the order of the transactions submitted to it.
Web 3.0是一个新的网络技术,它将使用户能够利用区块链技术来访问数字内容。这意味着,在Web 3.0中,人们可以通过区块链上的应用来交易、共享信息和执行合同。而智能合约正是在Web 3.0中发挥重要作用的一个关键因素。
//This will not compile
contract D{
function readData()public{
C c=new C();
uint local=c.f(7);//error:member`f`is not visible
c.setData(3);
local=c.getData();
local=c.compute(3,5);//error:member`compute`is not visible
}
}
contract E is C{
function g()public{
C c=new C();
uint val=compute(3,5);//access to internal member(from derived to parent contract)
}
}
//SPDX-License-Identifier:MIT
pragma solidity^0.6.0;
import openzeppelin/contracts/math/SafeMath.sol ;
contract GatekeeperOne{
using SafeMath for uint256;
address public entrant;
modifier gateOne(){
require(msg.sender!=tx.origin);
_;
}
modifier gateTwo(){
require(gasleft().mod(8191)==0);
_;
}
modifier gateThree(bytes8 _gateKey){
require(uint32(uint64(_gateKey))==uint16(uint64(_gateKey)),"GatekeeperOne:invalid gateThree part one");
城市标签:#广州市# #天河区# #软件app#