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, that I do not eat non-vegan dishes like meat, fish, poultry, or eggs. So, I get introduced to only those counters...