Just random things I learned about solidity

SolidityNotes.md

Using .call() or .delegatecall() we can call functions, similar to the data field in a sendTransaction

However, the function name being called must be encoded in hex so the first four bytes can be read as the function name. To do this, we use <address>.delegatecall(bytes4(keccak256("functionName()"))).

Simple logging is possible, using event and emit:

contract LogTest {
    event LogIt(string _text);
    
    //constructor
    function LogTest() public { 
        emit LogIt("Log Me!!!!");
    }
}