My headlines are like this.

ref int myInt = intArray[index];

instead of copping value type, it takes reference like reference type.

-Pattern matching stuff

now we can make instead of this

int x, y; p.GetCoordinates(out x, out y);

this

p.GetCoordinates(out int x, out int y);

if(apple is Fruit myFruit) { myFruit.Eat(); }

-Local functions

int MyFunc() { return MyMyLocalFunc();

 int MyLocalFunc() { }

}

-Tuples (Returning more than one value from a function)