Learn Blockchain by Building One
Blockchain is one of the biggest opportunities whose traces can be found even in the coming few decades. If you are associated with the technical industry, you are most likely to have heard of blockchain mechanisms. It is the latest underlying tech that lies behind every cryptocurrency and most decentralized apps.
Blockchain tech is considered to be the best invention of the era. Blockchain technology tracks all digital assets or data. The record is known as “ledger.” “Transaction” refers to every exchanged data. In this article, we are going to see how blockchain operates by making it in JS.

Why consider blockchain?
Blockchain was introduced in 2008 as a method of storing and securing digital currency. Blockchain was a proposal’s part created for bitcoin. The Blockchain network’s first application is bitcoin. The main advantage is that changes cannot be made in the recorded info without the involvement of every node or party. Some of the other advantages of Blockchain development services are as follows:
- Decentralized: The transactions take place on a computers’ network.
- Open: Every node can see the transactions.
- Immutability: Once a transaction is made, you cannot modify it.
- Security: Blockchain is highly secure because of encryption.
Beginning with the block:
Blocks are a box that possesses some vital information. Some of the properties of blocks are:
- Data for recording on the blockchain, for example, transaction data.
- The block hash is the block’s ID generated by making use of cryptography techniques.
- The hash of the previous block inside the chain is recorded in each block for linking it to the chain and improving its security.
- The timestamp of when the block was made and added to the blockchain.
- PoW or Proof of Work is the effort taken for deriving the hash of the present block.
Calculation of block’s hash:
The block’s hash is an identifier created by making use of the cryptographic strategy. The block hash will be received by hashing the prior block hash, timestamp, present block data, and PoW by making use of the SHA256 algorithm. Crypto will be put to use to hash the data. You can hire a reckoned blockchain app development company USA for expert advice, or you will have to do the following:
- Convert the data of the block to JSON format. It will enable us to connect it as a string with other info.
- The previous hash’s PoW, timestamp, data, and PoW need to be connected.
- Using the SHA256 algorithms, the earlier connection’s hash needs to be generated.
- The hash result needs to be returned with lowercase letters.
Mining latest blocks:
New blocks’ mining involves making the hash of the block with several leading zeros, which is offered by the level of difficulty of the present blockchain. It means that if the blockchain has a level 3 difficulty level, a block starting with three zeros needs to be developed.
As the hash will be derived from the content of the block, the content cannot be changed. But, the PoW can certainly be increased until the mining condition is satisfied. You can get in touch with any experienced blockchain development company to mine the new blocks.
For implementing this, mine() will be created for the Block class that will keep on incrementing the value of PoW and counting the block hash until a valid hash is received by us.
Defining the class of blockchain:
Three properties will be there in a blockchain glass- a number that denotes the level of difficulty, a genesis block, and a range consisting of other blocks inside the chain. The first block is the genesis block that is included in the blockchain.
A static method is declared within the blockchain for initializing a direct blockchain by making use of difficulty. Almost every Blockchain solution and services provider recommends making use of the difficulty level.
Addition of new blocks to blockchain:
After implementing the functionalities successfully for the blocks for calculating their hash, and then mine themselves.
The addBlock method is to be added to the prototype of the class of blockchain.
Validation of blockchain:
After implementing all the blockchain’s functionality, the blockchain’s authenticity needs to be checked for validating the blockchain that has never been tampered with. The isValid method can be added to the prototype of blockchain.
The hash of every block on the chain is recalculated and then compared with the hash id that is stored in them, and then also, the next block’s previousHash property is compared, and it must be equal to the hash ID of the present block. Most blockchain development experts recommend blockchain validation by following the right protocols.
Blockchain testing:
Because we have a completely functioning blockchain, all the features need to be tested after implementing them. The test function can be added to the files and run by making use of the node <filename.js> from the line of command. For testing, you may consider blockchain app development services to make sure that everything is in the right place.
Conclusion:
In this article, we have learned how blockchains operate and how to make blockchain right from scratch by making use of JavaScript. However, if you are not associated with the blockchain or lack knowledge about blockchain, it is recommended to seek professional help to get the work done.