Creating a whitelist so certain addresses can receive bonuses

Question

I am somewhat new to solidity and I am trying to create an ERC20 contract myself.

I would like to know how could I create a whitelist in order for the addresses on the list to receive a 10% bonus when buying.

Thank you! :)

Answer 1

how could I create a whitelist in order for the addresses

Create a mapping in which addresses are mapped to boolean (true or false). This boolean value represents the presence of the address.

mapping(address => bool) whiteList;

function addToWhiteList(address user){
     whiteList[address] = true;
}

Or, hard code address in the contract

whiteList[address1] = true;
whiteList[address2] = true;

Now, when user buys your token, check if the address is in whiteList or not.

if(whiteList[user]) transfer(normal plus 10% extra); else transfer(normal);