1. 1.
bitcoin 2, Ethereum: Ethereum is a kind of digital token of Ethereum, which is regarded as "bitcoin version 2.0". Using
blockchain technology different from bitcoin, "Ethereum" developers need to pay Ethereum (ETH) to support the operation of the application. Like other digital currencies, they can be traded on trading platforms. 3.
lettercoin: lettercoin (LTC, currency symbol:?) It is a kind of network currency based on "point-to-point" technology and an open source software project under MIT / X11 license. It can help users make instant payments to anyone in the world. 4. Dogcoin: dogcoin, known as "dogcoin / dogcoin", was born on December 8, 2013. Based on the crypt algorithm, dogcoin is the second largest
virtual currency in the world after bitcoin in terms of number of users. 5. Yuan Bao coin: Yuan Bao coin is a virtual
digital currency similar to bitcoin. The founder of yuanbaocoin is a group of bitcoin enthusiasts and the earliest supporters. However, after seeing the problem of bitcoin, he decided to do his best to develop an electronic currency suitable for Chinese people with the latest technology. 6. Diandiancoin: "ppcoin was pre released by sunny king on August 11, 2012 and officially released on August 19, 2012. Ppcoin's biggest innovation is that its
mining method combines POW workload proof and POS equity proof. POS mining method only needs ordinary computers and clients to process transactions and maintain network security, so as to achieve the purpose of energy saving and security. 7. Katecoin: katecoin (KTC for short) is a virtual P2P digital currency that can be used all over the world. Point to point transmission means a decentralized payment system. 8. Quark coin: Based on six encryption algorithms (black, BMW, groestl, JH, keccak, skein), 9 rounds of super secure hash operation of virtual currency, 3 rounds of application of random hash function, quark coin has unique technical specifications. 9. Infinity coin: Infinity coin (IFC) is a new digital currency, which has more circulation advantages than bitcoin, and fills the short board of bitcoin in the field of commercial circulation and promoting commercial operation. 10. Common coin: common coin, English name popular coin, short for POC, was born on March 7, 2014. The total POC is close to the world population (7.057 billion).
2. At the top of Ethereum is DAPP. It exchanges with the smart contract layer through Web3. JS. All smart contracts run on EVM (Ethereum virtual machine) and use RPC calls. Below EVM and RPC are the four core contents of Ethereum, including: blockchain, consensus algorithm, mining and network layer. Except DAPP, all other parts are in the Ethereum client. The most popular Ethereum client is geth (go Ethereum)
3. Ethereum is an open source public blockchain platform with smart contract function. It provides decentralized virtual machine (Ethereum virtual machine) to process point-to-point contract through its special cryptocurrency ether (also known as "Ethereum")
The token on the
blockchain is called ether, and the code is eth. It can be traded in many foreign exchange markets of cryptocurrency, and it is also the medium used to pay transaction fees and computing services on Ethereum
the concept of Ethereum was first proposed by vitalik buterin, a programmer, from 2013 to 2014, inspired by bitcoin, with the general meaning of "next generation cryptocurrency and decentralized application platform", and began to develop through ICO crowdfunding in 2014. As of February 2018, Ethernet is the second highest cryptocurrency in market value, second only to bitcoin
extended data:
Ethereum platform has no characteristics and value. Like programming languages, it's up to entrepreneurs and developers to decide what to use. However, it is clear that some application types benefit more from the functions of Ethereum than others. Ethereum is especially suitable for those applications that automatically interact directly between points or promote group coordination activities across networks
for example, coordinate the application of point-to-point market, or the automation of complex financial contracts. Bitcoin enables indivials to exchange money without the help of financial institutions, banks or governments. The impact of Ethereum may be more profound
in theory, any complex financial activities or transactions can be automatically and reliably carried out on Ethereum with coding. In addition to financial applications, any application scenario with high requirements for trust, security and persistence, such as asset registration, voting, management and Internet of things, will be affected by Ethereum platform on a large scale
4. curl方法，file_get_contents,
5. 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
6. Through curl to simulate, and then get the data, and use it in JSON format
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. t you," the matron said, "
9. There are people using ethna. What are you going to do??? Do you need to work on projects? error: Class \&# 39; Ethna_ AppManager\&# 39; not found? ? The reason for the problem is that you don't find ethna in your PHP file_ Appmanager class. Your problem can be solved by using the name of the ethna add app object table?? Among the generated files, the file I generated is called LDL_ User. PHP, add this? require_ once(\& quot; ethna.php\& quot;); Can solve, but the premise is your PHP. INI file include_ Ethna & # 92 has been added to path&# 92; The absolute path of class. This path is the path Apache searches when include and require. In addition, I didn't succeed in connecting Oracle with pear:: dB, but I succeeded in connecting mysql. It seems that Oracle can't run because of the SQL statement automatically generated by ehtna. I'm looking for the reason! Good luck
