Answer 1

Not sure what exampleFunc returns but I'm gonna assume it returns a reference in which case
exampleFunc() = 6;
is just shorthand for:
int& ref = exampleFunc();
ref = 6;

No need to explicitly create a variable called ref just to store 6 in it.

This only works if exampleFunc returns an lvalue, like references ( int& ).
It does not work with rvalues, like int, float, char.