Читать книгу Creation and Deployment of Smart Contracts on Ethereum Blockchain - Dr. Hidaia Mahmood Alassouli - Страница 6

 URL to open Remix IDE https://remix.ethereum.org

 When we compile the solidity code, we get byte code that we can deploy in Ethereum blockchain.

 Start new contract student.sol

 Below is smart contract code

pragma solidity ^0.4.18;

contract student {

string name;

uint age;

function setStudentDetails(string _name, uint _age) public{

name=_name;

age=_age;

}

function getStudentDetails() public view returns(string, uint){

return (name, age);

}

}

 We must deploy the smart contract on Blockchain. There are different blockchains available.Among them are: main net block chain and test net blockchains. Or we can deploy the smart conract on our self blockchain environment. We will use first to deploy smart contract on the inbuilt blockchain inside the Remix IDE which is Java Script VM.

 To deploy the smart contract on Java Script VM blockchain, we need an account. We get bay default in Remix 5 accounts. But if we deploy the smart contract in Ethereum blockchain, we must create an account there.

 We choose any account and deploy the smart contract on Java Script VM, click deploy. When the smart contract deployed, it will be deployed on some address. The address assigned by blockchain to that smart contract. So we can always refer to smart contract by that address only.

 We need ethereum to deploy the smart contract in the main net Ethereum blockchain. Because the miner will mine your transection and when itsis confirmed, it must get some fees.

 When you assign values to variables, you change the state of the variables, that means you make changes in block chain, and you must pay gas for that. Someone will mine the transaction and then it will be successful. Get function output the values of variables and does not change state of block chin. So it does not require mining and no fees required.

 Debugger allows you to debug the smart contract