Ethereum DAPP contract
Ethereum energy coin is not MLM
Ethereum is an open source public blockchain platform with smart contract function. Ethereum provides decentralized virtual machine (Ethereum virtual machine) to process point-to-point contract through its special cryptocurrency Ethereum
in 2013, vitalik buterin, 19, first mentioned the idea of Ethereum in a book entitled "Ethereum white paper: next generation intelligent connection and decentralized application platform". Then, in 2014, the algorithm and protocol of Ethernet coin were officially implemented, and $150 million was raised. The system itself was finally completed on July 30, 2015
as the representative of blockchain 2.0, the mainstream currency Ethernet is regarded as the wind vane of crypto digital currency market. However, over the past week, the price of ether currency has continued to fall. On August 14, 2018, the ethereal currency plummeted by 20%, reaching a record low of $257 this year. Compared with this year's peak of $1295, the price of Ethernet currency has shrunk by more than 80%. Affected by this, on August 15, 2018, none of the top ten mainstream currencies in the digital money market was spared, falling across the board, with a number of single day declines exceeding 10%
extended data
Ethereum started planning almost in 2013, and started to implement the project in 2015. Before that, there were many digital currencies imitating bitcoin in the market, and they made various modifications on the basis of bitcoin code. In this way, it is very difficult to develop a new blockchain application, to re deploy a new chain, and then to develop an application on this chain. Using a consensus mechanism of pow alone is a huge maintenance workload. It's like developing an app on a mobile phone and developing the Android system together
after Ethereum comes out, it is equivalent to the underlying operating system of the blockchain. On Ethereum, it is very convenient to develop various dapps without considering the underlying development, and it can also share the computing power and storage of Ethereum. For programmers, the threshold of blockchain development is lowered instantly. The emergence of Ethereum has played a very important role in the development and popularization of blockchain applications. That's why Ethereum is called blockchain 2.0
Thank you for your recommendation. Here I would like to share with you the following:
forsage international crowdfunding, the revolutionary smart contract technology of the new generation platform, originated from the development of Russian technical team, provides distributed market participants with the ability to directly engage in personal and commercial transactions. The smart contract of forsage distributed global shared matrix project is open and can always be viewed on the Ethereum blockchain. These are real smart contracts, which will be implemented on the Ethereum public chain forever without any third party tampering. The global shared matrix project is completely decentralized, aiming to preach Ethereum, so that more players can know Ethereum, smart contracts and forsage code btshijie
what is Ethereum
Ethereum is often compared with bitcoin, but the situation is different. Bitcoin is a kind of cryptocurrency and distributed payment network, which allows bitcoin to be transferred between users
the Ethereum project has a bigger goal. As Ethereum said, "Ethereum is a distributed platform running smart contracts.". These smart contracts run on "Ethereum virtual machine", a distributed computing network composed of all devices running Ethernet nodes
"distributed platform" means that anyone can set up and run an Ethereum node just as anyone can run a bitcoin node. Anyone who wants to run "smart contracts" on nodes must pay the operators of these nodes in ether, which is a cryptocurrency related to Ethereum. Therefore, the person running the Ethernet node provides computing power and gets paid in the Ethernet, which is similar to the way that the person running the bitcoin node provides hash power and pays in bitcoin
in other words, although bitcoin is only a blockchain and payment network, Ethereum is a distributed computing network, and its blockchain can be used for many other things. Details are provided in the Ethereum white paper
what is smart contract
smart contracts are applications that run on Ethereum virtual machines. This is a distributed "world computer" with computing power provided by all Ethereum nodes. Any node providing computing power will pay in ether digital currency as a resource
they are named smart contracts because you can write "contracts" that execute automatically when you meet the requirements
for example, imagine building a KickStarter like crowdfunding service on Ethereum. Someone can set up an Ethereum smart contract to pool funds to others. The smart contract can be written as follows: when $100000 of currency is added to the pool, it will be sent to the recipient. Or, if the $100000 threshold is not reached within a month, all currencies will be returned to the original holder of the currency. Of course, this would use ether instead of dollars
all this will be done according to the smart contract code, which can automatically execute the transaction without the need for a trusted third party to hold the currency and sign the transaction. For example, KickStarter charges 5% above the 5% payment processing fee, which means it will charge $8000 to $10000 for a $100000 crowdfunding project. Smart contracts don't have to pay a fee to a third party like KickStarter
smart contracts can be used for many different things. Developers can create smart contracts to provide functions for other smart contracts, similar to the way software libraries work. Alternatively, smart contracts can simply be used as applications to store information on the Ethereum blockchain
in order to really execute the smart contract code, someone has to send enough Ethernet tokens as the transaction fee - how much depends on the required computing resources. This costs the Ethereum nodes to participate and provide computing power. The global shared matrix project, which is completely decentralized, aims to preach Ethereum and let more players know Ethereum, smart contracts and forsage code btshijie
& quot; A smart contract is a set of promises defined in digital form, including the agreements on which the contract participants can execute these promises& quot;
let's explore the meaning of his definition in more detail
commitment
a set of commitments refers to the (often mutual) rights and obligations agreed by contract participants. These commitments define the nature and purpose of the contract. Take a sales contract as a typical example. The seller promises to deliver the goods and the buyer promises to pay a reasonable price
digital form
digital form means that contracts have to be written into computer-readable code. This is necessary, because as long as the participants reach an agreement, the rights and obligations of smart contract establishment are executed by a computer or computer network
to further explain:
(1) when will the parties to the smart contract reach an agreement? The answer depends on the specific smart contract implementation. Generally speaking, the contract is discovered when the parties are committed to the execution of the contract by installing the contract on the contract host platform< (2) contract execution
& quot; Execute & quot; And the real meaning of it also depends on implementation. Generally speaking, implementation means active implementation through technical means
(3) computer readable code
in addition, the contract needs specific & quot; Digital form & quot; Very much depends on the agreement that the parties agree to use
protocol
protocol is technical implementation, on this basis, the contract commitment is realized, or the contract commitment is recorded. Which agreement to choose depends on many factors, the most important of which is the nature of the assets being traded ring the performance of the contract
take the sales contract as an example. Suppose that the participants agree to pay in bitcoin. The chosen protocol will obviously be bitcoin protocol, on which the smart contract will be implemented. Therefore, the contract must use & quot; Digital form & quot; It's bitcoin scripting language. Bitcoin scripting language is a non Turing complete, imperative, stack based programming language, similar to forth.
a total of 22 weeks, divided into five stages,
the first stage is 4 weeks, go language foundation and network concurrency, learning the introctory go language,
the second stage is 4 weeks, go language practical web development, crawler development, cryptography, consensus algorithm, realizing lightweight public chain, learning the website and crawler that can develop golang, Achieve lightweight blockchain
stage 3, 4-week Ethereum source code analysis and smart contract DAPP development, master Ethereum core and smart contract development, as well as blockchain,
stage 4, 4-week super ledger, bitcoin EOS, source code analysis and smart contract practice, master super ledger development, cat bitcoin, bifurcated EOS after learning, As well as DAPP development of smart contract
phase 5, 6-week project practice, five enterprise level projects, and one year of blockchain project experience after learning
from the characteristics of the language itself, go is a very efficient language, which highly supports concurrency. Go language itself pays more attention to distributed system, and concurrency processing is relatively good, such as advertising and search, That kind of high concurrency server
go language advantages:
excellent performance, can be directly compiled into machine code, does not rely on other libraries, go is extremely fast. Its performance is similar to Java or C + +
concurrency is supported at the language level, which is the biggest feature of go. It is born to support concurrency, and go is the concurrency supported in gene, which can make full use of multi-core and make it easy to use concurrency
the built-in runtime supports garbage collection, which is one of the features of dynamic language. Although GC is not perfect at present, it is enough to cope with most of the situations we can encounter, especially GC after go1.1
it's easy to learn. The authors of go language all have the gene of C, so go naturally has the gene of C. There are 25 go keywords, but the expressive ability is very strong. It almost supports most of the features you've seen in other languages: inheritance, overloading, object, etc
rich standard libraries, go has built a large number of libraries, especially the network library, which is also my favorite part< As like as two peas, br / > built-in powerful tools, Go language is built with many tools chain, the best should be gofmt tools, automatic formatting code, make team review become so simple, code format is exactly the same, it is very difficult to think differently.
cross platform compilation and fast compilation. Compared with the sluggish compilation speed of Java and C + +, the fast compilation time of go is a major efficiency advantage
disadvantages of go language:
package management: package management of go language is absolutely not perfect. By default, it has no way to make a specific version of the dependency library, nor can it create replicable builds. In contrast, python, node and Ruby all have better package management systems. However, with the right tools, the package management of go language can also perform well
lack of development framework: go language does not have a major framework, such as Ruby's rails framework, Python's Django framework or PHP's laravel. This is a heated discussion in the go language community, because many people think that we should not start with using frameworks. This is true in many cases, but if you just want to build a simple crud API, it's much easier to use Django / djrf, rails laravel, or Phoenix
exception handling: go language can help developers deal with compilation errors by simply returning errors (or call stack) through functions and expected calling codes. Although this method is effective, it is easy to lose the scope of the error, so it is difficult to provide meaningful error information to users. Error package can solve this problem by allowing us to add context and stack trace to return error
another problem is that we may forget to handle errors. Static analysis tools such as errcheck and megacheck can avoid these errors. Although these solutions are very effective, they may not be the right way.
what is Ethereum
Ethereum is often compared with bitcoin, but the situation is different. Bitcoin is a kind of cryptocurrency and distributed payment network, which allows bitcoin to be transferred between users
related: what is bitcoin? How does it work
Ethereum has a bigger goal. As Ethereum says, "Ethereum is a distributed platform running smart contracts.". These smart contracts run on "Ethereum virtual machine", a distributed computing network composed of all devices running Ethernet nodes
"distributed platform" means that anyone can set up and run an Ethereum node just as anyone can run a bitcoin node. Anyone who wants to run "smart contracts" on nodes must pay the operators of these nodes in ether, which is a cryptocurrency related to Ethereum. Therefore, the person running the Ethernet node provides computing power and gets paid in the Ethernet, which is similar to the way that the person running the bitcoin node provides hash power and pays in bitcoin
in other words, although bitcoin is only a blockchain and payment network, Ethereum is a distributed computing network, and its blockchain can be used for many other things. Details are provided in the Ethereum white paper
what is ether
Ethernet is a digital token (or cryptocurrency) related to Ethereum blockchain. In other words, Ethereum is the token and Ethereum is the platform. But now people often use these terms alternately. For example, coinbase allows you to buy Ethereum, which stands for Ethereum
this is technically "altcoin", which actually means a non bitcoin cryptocurrency. Like bitcoin, ether is supported by distributed blockchain - in this case, Ethereum blockchain
developers who want to create applications or Ethereum smart contracts on Ethereum blockchain need Ethernet token to pay for nodes to host it, while users of Ethereum based applications may need Ethernet to pay for services in these applications. People can also sell services outside the Ethereum network and accept Ethernet payments, or they can sell Ethernet tokens in cash - just like bitcoin
DAPP is the abbreviation of Chinese distributed app for decentralized application
a DAPP has background code running in a distributed peer-to-peer network. The background code of traditional app is running on the centralized server
the front-end code of a DAPP can be developed by any language, just like the traditional app. In addition, DAPP's front-end code can be hosted in distributed storage services, such as swarm or IPFs
If an application = front end + back end, because Ethereum contract is composed of code running in Ethereum distributed point-to-point network, distributed application = front end + contract
the picture shows a DAPP architecture:
app we all know that it is a client application, which is the abbreviation of application. DAPP is d + app, and D is the first letter of English word decentralization. Chinese word translation is decentralization, that is DAPP is decentralized application. This is to understand the concept literally. To form a clear, accurate and necessary concept in the brain, we need to understand DAPP in depth
compared with app, the biggest difference between them is centralization and decentralization. App needs money first, so it needs financing first; Then there will be more people, so we will develop and operate after recruiting all the people. DAPP is the proct of inheriting traditional app and combining the characteristics of blockchain, which is more like crowdfunding mode, sharing mode and decentralization mode
continue to dig 75 in Ag
go back to learn skills and go to the thousand layer stone forest. Dig slowly
you will want to die
. If you have money, buy some mines to melt