The fastest gas configuration of Ethereum smart contract

1.

The smart contract has been written for a long time

if they can add changes, the description is centralized

the contract is written into the Ethereum smart contract, which is a contradiction sentence

the financial customer service doesn't understand, which is very unreliable

community sites

2. Go full stack + blockchain course:
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.

3.

Hello, according to my experience, 1. First set up the rack, then fix the graphics card, and then plug the CPU and fan, memory, SSD hard disk into the slot of the motherboard, and connect the power supply and motherboard power supply

I hope my suggestions can help you, thank you

4. Because blockchain technology has natural advantages in realizing smart contracts. Bitcoin, Ruitai, Laite, Ethereum and other digital cryptocurrencies all use blockchain technology. Blockchain is an important concept of bitcoin. In essence, it is a decentralized database and the underlying technology of bitcoin. Blockchain is a chain of uses

5. Ethereum is a distributed computing platform. It generates an cryptocurrency called ether. Programmers can write "smart contracts" on the Ethereum blockchain, and these Ethereum smart contracts will be executed automatically according to the code

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

6. The core component is the graphics card, which accounts for about 80% of the cost, followed by the motherboard and power supply

8. In short, this is the function of the central bank
new currencies are usually solved through open market operations. In other words, the central bank makes its own money flow out by buying Treasury bonds (issued by the Ministry of Finance), so that the money flows to commercial banks, and commercial banks make money circulate in the society through lending
first of all, understand currency: today's commonly referred to as currency is the paper money in our pocket. It is a medium and tool to facilitate the exchange and circulation of goods under the commodity economy. It has no value in itself and is issued and forced to circulate by the national bank. When you go shopping in China with us dollars, the shop owner will treat us dollars as a piece of waste paper, because US dollars must be converted into RMB through the central bank to be used in China
currencies of different countries cannot be circulated in different countries. Now, with the global economic integration, there are certain economic exchanges between countries. In order to solve the trade and currency problems between different countries, two concepts of foreign exchange and foreign exchange reserve are involved
as we all know, a country's wealth is not measured by the amount of its currency issued or owned, but by the amount of its commodities, which are the material needs of people's life, rather than money, that is, a country's proction capacity and gross domestic proct
trade between countries can be divided into export and import as follows:
in the case of export, if US dollar is used as foreign currency, that is to say, Chinese multinational enterprises sell their procts in the United States in exchange for the currency of other countries. For Chinese people, foreign currency is not allowed to circulate in the Chinese market, Therefore, in the Chinese market, foreign currency is equivalent to a pile of waste paper. Therefore, it is useless for Chinese export enterprises to sell foreign currency to the national bank to exchange it for RMB, and the state holds foreign currency. People's wealth is ultimately reflected in their material enjoyment, and money is only an intermediary and tool for material exchange, Our domestic enterprises give the goods they proce to the United States, while the United States only gives us foreign currency (bonds), thus forming a debt relationship: that is, China is the creditor, foreign countries (the United States) are the debtor, and foreign exchange (US dollars) is the debt relationship certificate

for the import situation, foreign currency reserves will not be affected. For example, if foreign businessmen sell foreign goods at home to earn RMB, the central bank will take the foreign exchange reserves (US dollars) to buy back RMB from foreign investors (because this part of RMB is circulating at home and is not counted as foreign exchange reserves), It may also be that foreign businessmen take RMB to their own country to exchange for their own currency, which also forms their own foreign exchange reserves (whether the actual process is like the above, I don't know, it's not studying economy, it's just speculation). Buy back is actually a hedging process (the real sense of hedging seems to be that the central bank takes foreign exchange to buy overseas). It can also be understood as follows: foreign goods are regarded as the goods proced by the central bank and sold in the domestic market. In this way, part of the foreign exchange reserve is returned to the people through the central bank, and the debt is also paid

generally, the amount of money in circulation of a country corresponds to the amount of goods proced by the country Material wealth corresponds to the amount of money)
Chinese enterprises export goods, which can be seen as: China proces too many domestic goods (that is, the corresponding currency is not enough),
domestic enterprises get foreign markets for commodity sales and exchange through the form of export, and can exchange domestic goods for foreign goods, but because of the existence of foreign currency, In fact, these foreign currencies are equivalent to the debts of foreign consumers to China's export enterprises, and these debts are uniformly assigned to the name of the national bank. This has become the country's foreign exchange reserves. The more foreign exchange reserves, the more money the state will lend. Lending is equivalent to issuing money. If a country releases too much money, it needs to issue a large amount of money, which may cause inflation (there are not enough goods, but a lot of currency in circulation). At this time, the country purchases goods from overseas through the international market, and consumes foreign goods in exchange for goods, so as to achieve the goal of stabilizing and balancing the economy. It can also be understood from another perspective that the central bank releases a large amount of money to exchange for foreign exchange reserves. The increase of this kind of money is not caused by the "invisible hand" of the market rules, but by the Central Bank of the government. If we zoom in, the increase of money will actually be inflation, and the money on the hands of the people will be devalued, The devalued part is occupied by the central bank free of charge. Therefore, it can be understood as: foreign exchange reserves are liabilities of the central bank, not assets, because it is exchanged by the central bank from the people's hands with RMB, then the people will want to cash this asset one day
as China's foreign exchange currency is mainly US dollar, once the US economy fluctuates and leads to the depreciation of US dollar, China's foreign exchange reserves will have the risk of devaluation. The devaluation of foreign exchange reserves is also the loss of China's assets< In a word, foreign exchange reserve is a kind of debt relationship between the people and other countries (reserves are not national assets, but the money of the working people), and the people, as one of the creditor's rights, transfer the creditor's rights to the National Central Bank and hang them in the name of the central bank

foreign exchange reserve refers to the foreign convertible currency held by a country's monetary authority and can be used for external payment, which acts as an international reserve asset. The amount of foreign exchange reserve mainly depends on the status of import and export, the scale of foreign debt and the actual use of foreign capital. Foreign exchange reserves are used for trade with other countries
in order to increase foreign exchange, we need to issue RMB to buy, and the supply of RMB will increase, which may cause monetary expansion in the domestic market. A certain amount of foreign exchange reserve is an important means for a country to adjust its economy and realize the economic balance at home and abroad. When there is a deficit in the balance of payments (more imports, the domestic market full of foreign goods, causing domestic monetary tightening), the use of foreign exchange reserves can promote the balance of payments; When the domestic macro-economy is unbalanced and the total demand is greater than the total supply (the consumption demand increases and the goods are not enough), we can use foreign exchange to organize imports, so as to adjust the relationship between the total supply and the total demand and promote the macro-economy balance
at the same time, when the exchange rate fluctuates, we can use the foreign exchange reserves to intervene the exchange rate and make it stable
the performance of foreign exchange reserves is to hold a kind of financial claims expressed in foreign currency, not put into domestic proction. This leads to the problem of opportunity cost, that is, if the monetary authorities do not hold reserves, they can use these reserve assets to import goods and services, increase the real resources of proction, and thus increase employment and national income, while holding reserves gives up such benefits
the increase of foreign exchange reserves should expand the money supply. If the foreign exchange reserves are too large, it will increase the pressure of inflation and increase the difficulty of monetary policy
holding too much foreign exchange reserves may also cause losses e to the depreciation of foreign exchange rate
because foreign currency can not circulate in the domestic market, the central bank not only releases a certain amount of money (through export and foreign capital) in China, but also reserves a certain amount of foreign exchange on behalf of the country. At this time, RMB is used in China, while foreign exchange itself is independent of the domestic economic operation, and is used by the central bank to maintain and increase value in the international financial market.

9. Last time, I cooperated with Shengshi Huacai company in Shenzhen. Shengshi Huacai company knows a lot about the development of blockchain system, and many companies are looking for them to do blockchain system.

10. You can choose by yourself, and the minimum gas quantity is different for different contracts. General minimum 6000gas