Why I can only use switch statements in C++ only for intergers?

Answer 1

You can use them for every primitive datatype.

Answer 2

sorry you can't proof that
(╯°□°）╯︵ ┻━┻
the switch accepts cases of the same type, look 👇.

switch (8) {} // where 8 is integer
you can only use integers as cases

switch ("8") {} // where 8 is string
you can only use strings as cases

Answer 3

Switch is used for all primative data types.