Is it possible to connect two inputs?

Question

Arduino

Is it possible to connect two inputs, that is, receive a signal from one input and transmit it to another? If yes, please provide an example code. Thanks in advance
PS The point is to transfer a signal (music) from a 3.5 mm cable to another 3.5 mm cable via Arduino, is this possible?

Answer 1

Made with a relay

Answer 2

If the input transmits data, then this is already an output ...

Answer 3

I allow!

...
  pinMode(4, OUTPUT);
  pinMode(5, INPUT);
  digitalWrite(4, HIGH);
...