The completed program is given below.
In completing the program, be sure that rate is correct. The user is supposed to enter percent interest, for example 6 for six percent. The program needs a decimal fraction such as 0.06 to work correctly.
import java.io.*; class dollarsAfterForty { public static void main( String[] args ) throws IOException { double dollars = 1000.00 ; double rate; int year = 1 ; // get the interest rate from the user String rateChars; BufferedReader stdin = new BufferedReader( new InputStreamReader(System.in) ); System.out.println("Enter the interest rate in percent:"); rateChars = stdin.readLine(); rate = ( Double.valueOf( rateChars ) ).doubleValue(); rate = rate/100.0; while ( year <= 40 ) { // add another year's interest dollars = dollars + dollars*rate ; // add in this year's contribution dollars = dollars + 1000 ; year = year + 1 ; } System.out.println("After 40 years at " + rate*100 + " percent interest you will have " + dollars + " dollars" ); } } |
Here is an example of a user dialog with the program:
C:\users\default\JavaLessons/chap16>java dollarsAfterForty Enter the interest rate in percent: 11 After 40 years at 11.0 percent interest you will have 646826.9337201559 dollars C:\users\default\JavaLessons/chap16>java dollarsAfterForty Enter the interest rate in percent: 12 After 40 years at 12.0 percent interest you will have 860142.3907860613 dollars C:\users\default\JavaLessons/chap16>java dollarsAfterForty Enter the interest rate in percent: 13 After 40 years at 13.0 percent interest you will have 1146485.7949682677 dollars