One Solidity type that was not discussed in the last chapter is the var data type. var is a special type that can only be declared within a function. There cannot be a state variable in a contract of type var. Variables declared with the var type are known as implicitly typed variable because var does not represent any type explicitly. It informs the compiler that its type is dependent and determined by the value assigned to it the first time. Once a type is determined, it cannot be changed.
The compiler decides the final data type for the var variables instead of a developer mentioning the type. It is therefore quite possible that the type determined by the block.difficulty (uint) current block compiler might not exactly ...
