boolean b = true; // Assign true to b
println(b); // Prints "true"
println(!b); // Prints "false"
b = !b; // Assign false to b
println(b); // Prints "false"
println(!b); // Prints "true"
println(5 > 3); // Prints "true"
println(!(5 > 3)); // Prints "false"
int x = 5;
println(!x); // ERROR! It's only possible to ! a boolean variable