Hashing the data

The next method that we are going to look at and add into our blockchain data structure is called hashBlock. What this hashBlock method will do is take in a block from our blockchain and hash its data into a fixed length string. This hashed data will appear randomly.

In essence, what we're going to do is pass some blocks of data into this hash method, and in return we'll get a fixed-length string, which will simply be a hash data that is generated from the data that we passed in or from the block that we passed.  

To add the hashBlock method to our blockchain data structure, type the following line of code after our createNewTransaction method: 

Blockchain.prototype.hashBlock = function(blockdata) {

}

In our hashBlock method, blockdata will be the input data of our block from which we want to generate the hash.  

So, how can we take a block or blocks of data and get a hashed string in return? For generating hash data, we're going to use a hashing function called SHA256.