Mastering Blockchain Programming with Solidity

Using variable and function visibility

Solidity state variables and functions should have visibility defined, along with their declaration. This visibility defines how a function and a state variable will be accessible from within the contract, as well as from outside of the contract.

There are four different visibility modifiers, that is, public, external, internal, and private, present in Solidity:

• public: A function defined as public is accessible from both inside and outside of the contract. Solidity generates a getter function for public state variables, and these are also accessible from outside of the contract via these getter functions.
• external: A function defined as external is only accessible from outside of the contract. Internally, ...