You use switch for one variable compared against many specific constant values. You use if-else for ranges, complex conditions, or non-constant comparisons. I'll show you: switch (menuOption) with cases 1, 2, 3, 4 is clearer than four else if statements.
But if (age >= 18) can't become a switch because you test a range, not specific values. Switch only works with integers and characters, not strings or floats. If you need to compare strings or use && or ||, you must use if-else instead.