Question

why cant i read this single character?

char c = 'Y';
    while(c == 'y' || c == 'Y'){
        //stuff happens..
    }
    c = (char)System.in.read();   <----error

I get a compilation error that says “Unhandled exception type IOException”

Answer 1

You have 2 options to solve this:

1. Handle the exception using a try-catch statement as shown below:

   char c = 'Y';
   while(c == 'y' || c == 'Y'){
       //stuff happens..
   }
   try {
   
       c = (char)System.in.read();
   
   } catch (IOException e) {
   
       e.printStackTrace();//or however you choose to handle this
   }
   

Below the package statement in class (if any), add an import statement like:

        import java.io.IOException;

2.
Add a throws clause after the function indicating that the funcion may throw a checked exception. In this case you may want to handle the exception in the calling function.

Example: Suppose function sample () calls test()

public static void test() throws IOException {

    char c = 'Y';
    while(c == 'y' || c == 'Y'){
        //stuff happens..
    }
    c = (char)System.in.read();

}

Below the package statement in class (if any), add an import statement like:

        import java.io.IOException;

In case 2 you may handle the exception in sample() else the exception (if occurred) will propagate upwards until it is handled.