Increment and decrement operations using Solidity

Figure 3.10 shows the code of an increment and decrement operation in Solidity. It also has a function that takes input, and a function, that fetches out this number once the contract gets executed:

Figure 3.10: Increment and decrement operation using Solidity (ArithValue.sol)

Isn't this code a bit more complex than the hello world contract? Let me walk you through this code. The first line starts with pragma. As you have realized already, it just states which version of Solidity we are about to use. In our case, we are using version 0.4.11. As I type, remix IDE supports versions up to 0.4.16.

To understand pragma, let us go back to our brunch buffet analogy from Chapter 2, Grokking Ethereum. If I specify during the buffet reservation that I am a strict vegan, I am giving the buffet organizers some sort of directive, in advance...