Ethereum tutorial 2018

1. Ethereum is not a kind of currency, but a decentralized intelligent protocol. It can be understood as a huge global account book. The logic of this intelligent protocol does not need a specific server to support its daily operation. Instead, it is the protocol terms given by the executors before entering among the scattered users. This is an application evolved from decentralization
compared with bitcoin, we can find that Ethereum is more difficult to develop a new encryption technology than bitcoin. This breakthrough has greatly reced the development cost and time for developers who apply blockchain technology. The emergence of Ethereum once again reiterated the need to split the center, as well as the feasibility and advantages of decentralized distributed applications, to the existing economic market, the financial sector a new direction of development and throw to the society a new entrepreneurial ideas and opportunities.

2.

If you want to query the transaction records on the main network, you can use Etherscan. However, if you build your own private chain, how should you query the transaction records

the answer is that you need to listen to the logs on the chain, save them in the database, and then query them in the database. For example:

< pre t = "code" L = "Java" > varaddr = & quot& quot;< br />varfilter=web3.eth.filter({fromB lock:0 ,toBlock:' latest', address:addr });< br />filter.get(function(err,transactions){
transactions.forEach(function(tx){
vartxInfo=web3.eth.getTransaction(tx.transactionHash);
/ / at this time, the transaction information txinfo can be stored in the database
})< br />});

Web3. Eth. Filter() is used to monitor the log on the chain, and Web3. Eth. Gettransaction() is used to extract the information of the specified transaction. Once the transaction information is obtained, it can be stored in the database for query

recommend a practical introction, you can see: Ethereum tutorial

3. Of course, it's worth investing. Ethereum has broken a new high for the second time. It's up to $1414, but we don't recommend catching up. Can go to the currency to play spot, currency spot trading, safe and stable, not burst. Suitable for ordinary investors.

4. 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.

5. The network will be upgraded to Constantinople & Petersburg at block height of 7280000. L, Z, b show that it will be upgraded on March 1, 2019 Beijing time. I don't know if the upgrade is successful

6. It seems that there will be step prompts on the platform. When registering the domain Kingdom, just follow the prompts directly. It's not difficult.

7.

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:

8. How to earn money by raising cats
on cryptokitties, you can buy virtual cats. By 17:00 Beijing time on December 6, 2017, the cheapest kitten had reached 0.037eth. Equivalent to 110 yuan per piece
then the kittens have some opinions about the generation. For example, Gen 12 indicates that it is the 12th generation, while Gen 20 indicates that it is the 20th generation. Generally speaking, the smaller the algebra, the more valuable it is. And you can make your kittens slap each other. For example, a Gen 1 kitten and a Gen 1 kitten will give birth to a Gen 2 kitten
you can sell your kittens and their offspring for money
but what if you don't have two kittens? If you only buy one kitten, you can use your kitten to have fun with other people's high-quality kittens. The fee also depends on the kittens (to be honest, this mechanism is very evil, similar to... Borrowing chickens to have children?) The quality of the proct. If your kitten is of high quality, you can also use your kitten to mate other people's kittens, and then you get Ethereum income
but kittens also have special fertility rates

every time a kitten gives birth to one generation, it will have a certain cooling time, and it can't regenerate kittens within the cooling time,
the cooling time is divided into several grades
fast: 1 minute
swift: 2 – 5 minutes
snappy: 10 – 30 minutes
brisk: 1 – 2 minutes
plodding: 4 – 8 minutes
slow: 16 – 24 minutes
sluggi Sh (lazy kitten): 2 – 4 days
catatonic (nervous kitten): 1 week
so the price of your cat also depends on its birth time
and generally speaking, the larger the algebra is, the higher the gen value is, and the slower their growth rate is
but I want to make complaints about it because CryptoKitties is too hot! Ethereum network has a little bit of a crash, the official recommended that every time you buy a cat, the minimum handling charge is 21000. 400000 fuel = 0.01eth. However, it is irritating that I raised the procere to 1.6 million fuel, which is 0.04, and Ethereum still failed. 0.04 Ethereum. That's more than 120 yuan. It's too dark.