Ethereum development course

1.

Ethereum is an implementation of blockchain. In Ethereum network, many nodes are connected with each other to form Ethereum network:

Ethereum node software provides two core functions: data storage and contract code execution

in each Ethereum node, complete blockchain data is stored. Ethereum not only saves the transaction data on the chain, but also saves the compiled contract code on the chain

At the same time, a virtual machine is provided to execute the contract code

Ethereum virtual machine

Ethereum blockchain not only stores data and code, but also contains a virtual machine (EVM) in each node to execute contract code - it sounds like a computer operating system

in fact, this is the core difference between Ethereum and bitcoin: the existence of virtual machine has brought blockchain into the era of 2.0 and made blockchain a friendly platform for application developers for the first time

the above content comes from the introction course of Ethereum DAPP development

2.

EOS is a public chain system at the bottom of blockchain developed by block. One, which is specially designed to support decentralized application of Commerce, and its code is open source

bitcoin is called blockchain 1.0 because it opens up the world of digital cryptocurrency and takes a decisive step from 0 to 1

Ethereum is known as blockchain 2.0, because it provides Turing complete virtual machine that can run smart contracts, bringing unlimited possibilities

and EOS is called blockchain 3.0, why? Two words: performance

The positioning of EOS is the slogan of its home page:

English: the most powerful infrastructure for decentralized applications

Chinese: the most powerful decentralized application infrastructure

EOS expects to be an enhanced version of Ethereum, a high-throughput intelligent contract platform

although Ethereum has complete functions, it is limited by its design choice. Due to the block output speed of 15 seconds, the transaction throughput is far from large-scale practical level, which is only about 30 ~ 40tps (transaction / s). EOS, on the other hand, has chosen a different technology route, with the goal of achieving a considerable million TPS, which is quite attractive considering visa's actual processing speed of 1700tps

consensus mechanism of EOS

the reason why the throughput of bitcoin and Ethereum is so low is that they are constrained by the application scenario they envision and the consensus mechanism they choose for the scenario - both of them assume that the environment in which the system runs is totally untrustworthy, so they both adopt the consensus mechanism of proof of work

consensus, as the name suggests, is to reach a unified understanding of something - for blockchain, something refers to the confirmation of the transaction - any node to submit a transaction needs everyone's approval

the pow mechanism currently adopted by bitcoin and Ethereum is the design of the legendary Nakamoto Tsung. Under this mechanism, in order to obtain the bookkeeping right and digital currency reward, miners need to constantly dig for the compliant hash value, and confirm and package the transaction data through the consensus of hash value. POW has no access threshold, and any node has equal rights to participate in bookkeeping. Of course, the probability of winning is related to computing power:

the price of ram is based on Bancor algorithm, that is, it is regulated by market supply and demand: if the supply of ram exceeds the demand, more EOS certificates are needed to buy ram, At this time, more EOS certificates can be obtained by selling ram

memory is a consuming resource, which cannot be redeemed and can only be bought and sold. Take the issue of currency on EOS as an example. At present, the issue of currency requires 20m of memory. An EOS can buy 20KB. According to the current storage price, issuing a currency will consume 1000 EOS. This is the source of EOS memory consumption

Course Overview

this course is for friends who are interested in the development of EOS decentralized application. The course covers the core concepts of EOS DAPP development, the development and deployment of smart contracts, and how the front page interacts with EOS blockchain. Finally, a complete DAPP development based on react and EOS is completed

Chapter 1: enter the world of EOS

to understand the core concepts of EOS, such as positioning and characteristics, consensus mechanism, payment computing model, etc

Chapter 2: Hi EOS

understand the overall framework of EOS node software and the functions of node server, wallet server and command-line tools, learn how to configure and start EOS node server and wallet server, and preliminarily understand the use of command-line tools

Chapter 3: wallet, key and account

understand the three core concepts related to personal identity in EOS: wallet, key and account, and learn how to use command-line tools to create wallet, key and account

Chapter 4: development and interaction of smart contracts

understand the concept and function of smart contracts, learn how to write and compile EOS smart contracts, and learn how to deploy and interact with contracts using command-line tools

understand the persistence mechanism of state in EOS smart contract, and learn to use multi index table to save contract state

Chapter 5: issue your own tokens

learn the principle and implementation mechanism of issuing tokens on EOS, and master how to use command-line tools to issue, transfer and view the balance of tokens through practical operation

Chapter 6: use code to interact with smart contract

understand the principle of interaction between application and EOS blockchain, and learn to use JSON RPC interface and eosjs encapsulation library to access EOS blockchain

Chapter 7: DAPP development of practical notes

comprehensively use EOS knowledge, use react to complete a decentralized application of EOS notes, and learn the complete process from requirement analysis to code implementation

The above course address is as follows: EOS tutorial

3. The core component is the graphics card, which accounts for about 80% of the cost, followed by the motherboard and power supply, with high configuration. If you're digging deep in the mountains with a large mining machine. If personal computers are not enough for electricity, you can also choose crowdfunding mining machine... And now mining is generally in the place where electricity is cheaper, and the money is usually directly linked to the platform (currency exchange trading platform). Personal suggestions should be considered. After all, electricity is not enough.

4. It belongs to the third stage of Ethereum development, the metropolitan stage. At this time, we enter the POS, energy saving, and proof of rights and interests, resulting in less new Ethereum.

5. Ethereum architecture consciousness is the 6-tier architecture of regional block chain. They are: data layer, network layer, consensus layer, incentive layer, contract layer and application layer. I personally feel that the best thing to do in Ethereum development is Shengshi Huacai, which is very professional

6. Shengshi Huacai company has done a good job in the development of Ethereum.

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8. My computer - & gt; Attribute - & gt; Advanced - & gt; Environment variables - & gt; Add the following environment variables to the system variables:
java_ The home value is: the directory where JDK is installed, and mine is C: &# 92; Program Files\ Java\ jdk1.6.0_ 34
the classpath value is:;% JAVA_ HOME%\ lib\ tools.jar;% JAVA_ HOME%\ lib\ dt.jar;% JAVA_ HOME%\ bin;( Pay attention to the & quot& quot; To add)
Path: append at the beginning.;% JAVA_ HOME%\ bin;% JAVA_ HOME%\ jre\ bin;( Pay attention to the & quot& quot; To add)

after the installation, you can check whether the JDK is installed successfully. Open the CMD window and enter Java – version to view the version information of JDK.

9.

Ethereum specifies the JSON RPC API application development interface that each node needs to implement. This interface is transport independent. Applications can use this interface protocol to operate Ethereum nodes through HTTP, websocket or IPC and other communication mechanisms: