Why is this loop a sentinel-controlled loop?
The sentinel value "n" terminates the loop.
Here is the program, with some work done on reading a value for "x". (Look in Chapter 11 to review floating point input.)
import java.io.*; class evalPoly { public static void main (String[] args ) throws IOException { BufferedReader userin = new BufferedReader(new InputStreamReader(System.in) ); String xChars; // character version of x, from the user double x; // a value to use with the polynomial String response = "y"; // "y" or "n" while ( response.equals( "y" ) ) { // Get a value for x. __________________________________________ ; __________________________________________ ; // convert data in character form to floating point form x = Double.parseDouble( xChars ); // Evaluate the polynomial. // Print out the result. // Ask the user if the program should continue. System.out.println("continue (y or n)?"); response = userin.readLine(); } } }