What is a 0 address check?

[SquilliamX]

what is a 0 address check, how does someone implement it, and how do we test for it?

[alymurtazamemon]

@SquilliamX It is just a validation check to make sure the input address parameter is initialized and is not a zero address which is the default value for address type.

You can add the require and assert statements in the solidity code to make sure the variables of address types are not empty.