编写应用合约之前,先弄清它的逻辑,有助于我们更好的部署合约 pragma solidity ^0.4.21; pragma experimental ABIEncoderV2; contract voter1{ //voter candidate //["eilinge", "lin" ,"meimei"] //admin 0x4B0897b0513fdC7C541B6d9D7E929C4e5364D2dB //0x14723a09acff6d2…

pragma solidity ^0.4.4; contract funder{ //0xca35b7d915458ef540ade6068dfe2f44e8fa733c //0x14723a09acff6d2a60dcdf7aa4aff308fddc160c :10 //0x583031d1113ad414f02576bd6afabfb302140225 :20 struct Funder{ address addr; uint amount; } struct Campaign{ addre…

pragma solidity ^0.4.0; contract test { uint [5] T =[1,2,3,4,5] ;//固定长度的数组:可修改数组内值大小,不支持push,不可更改长度 /* contract test { uint [] T = new uint[](5); //ParserError: Expected identifier but got 'storage' //全局数组,默认创建在storage中,无法创建在memory中,长度可修改 function se…

pragma solidity ^0.4.10; contract Delete{ /* delete可用于任何变量(除mapping),将其设置成默认值 bytes/string:删除所有元素,其长度变为0 bytes32:重置所有索引的值 mapping:什么都不会发生 mapping(key=>value)中的key:删除与该键相关的值 */ string public str1 ='nihao'; function deletstr() public{ delete str1; } fu…

pragma solidity ^0.4.0; contract modifierTest{ uint public v1; uint constant v2 =10; //uint constant v3; Uninitialized "constant" variable string public v4='test1'; string constant v5='test2'; //string constant v6;Uninitialized "constant&qu…

创建一个基于以太坊平台的分红币MNC,根据持有的代币数量,进行分红的算法.github地址: https://github.com/lxr1907/MNC 1.使用以太坊根据比例换购token MNC 2.定期根据使用用户资金购买的矿机挖ETH,打入该合约,触发分红方法根据token持有比例分红 3.衰减,由于矿机有折旧衰减损坏的概率,token会随着持有时间而衰减. 代码如下 pragma solidity ^; contract owned { address public owner; f…

1.环境安装 1) node安装 设置镜像地址: curl --silent --location https://rpm.nodesource.com/setup_8.x | bash -下载安装 yum -y install nodejsnode -v 查看版本: 2)安装truffle $npm install -g truffle 3)安装python npm install python 2.创建truffle项目 我的项目安装在 /usr/local下. 所以分别执行下面三个命令:…

从这周开始,开始学习以太坊开发--solidity,开始决定往区块链方向发展,毕竟区块链技术应用广泛.一开始接触solidity开发语言不太习惯,毕竟一直在学习python语法,有很多都不能接受.有难度,我喜欢!! 成功者往往会选择走人少走的,更艰难的路,只有做别人都很难实现的事,再加上个人加倍付出的努力,成功才更有意义!!! pragma solidity ^0.4.0; contract Test{ string str1; uint8 _age; uint8 _height; uint8…

pragma solidity ^0.4.0; contract EMath{ string public _a="lin"; function f() public{ modify(_a); } //function modify(string storage name) private{ function modify(string memory name) private{ //string storage c = name;Type string memory is not i…

pragma solidity ^0.4.0; contract Test{ /* 属性的访问权限 priveta public internal defualt internal interlnal,private cannot be accessed from outside */ uint8 internal _money; uint8 _age; uint8 private _height; uint8 public _sex; /*uint8 public _sex == functi…