ERC20合约内部余额/转账

Question

It is possible (even if I do not see the point yet) to send some tokens to its ERC20 contract itself even if Metamask warns you about sending to a contract.

I wondered a few things, let's say I have deployed an "ABC" ERC20 token contract:

1. Is there any point at all for that ERC20 token contract to hold ABC tokens or even other tokens in it?
2. If I send some ABC token to the ABC ERC20 token contract address, how should/could I call approve/transfer or transferFrom from an ABC ERC20 contract function in solidity to get them sent to a given address (I store the "owner" address used for deployment for instance)?

I hope this does make sense to someone;)

Thanks !

Answer 1

1. Is there any point at all for that ERC20 token contract to hold ABC tokens or even other tokens in it?

Built-in buy and sell functions that allow you to partially control the token market price through arbitrage between your own contract and DeX pools. For this, your contract needs to hold sufficient amounts of both ABC and USDT.

Example: Your contract implements functions that allow users to buy 1 ABC token for 1 USDT, and sell 1 ABC token for 0.99 USDT. If the current price in a DeX pool is 1.05 USDT, arbitrage traders can buy ABC from your contract for the fixed price of 1 USDT and immediately sell it in the DeX pool - effectively balancing the DeX pool liquidity amounts up to the point where the price in the DeX pool reaches 1 USDT as well.

2. If I send some ABC token to the ABC ERC20 token contract address, how should/could I call approve/transfer or transferFrom from an ABC ERC20 contract function in solidity to get them sent to a given address (I store the "owner" address used for deployment for instance)?

Your ABC contract needs to implement a custom function to withdraw the tokens from its address. Example using OpenZeppelin libraries:

contract ABC is ERC20, Ownable {
    // allows the owner to withdraw `amount` of ABC tokens from the ABC contract
    function withdraw(uint256 amount) onlyOwner {
        _transfer(address(this), owner(), amount);
    }
}