What are abstract contracts in Solidity?

What are abstract contracts in Solidity?

Abstract contracts in Solidity are contracts that cannot be instantiated directly and may contain unimplemented functions.

Can you give me an example of an abstract contract?

Sure! Here's a simple example:

abstract contract Animal {
    function makeSound() public virtual returns (string memory);
}

How do I inherit from an abstract contract?

You can inherit from an abstract contract by creating a new contract that implements the abstract functions. For example:

contract Dog is Animal {
    function makeSound() public override returns (string memory) {
        return "Bark";
    }
}

What happens if I don't implement the abstract functions?

If you don't implement the abstract functions in the derived contract, it will also be considered abstract and cannot be instantiated.