Debugging Practice

The way the variable rate is initialized and then immediately incremented is awkward. Here is a possibly buggy program that does this in a different way:

class  MillionDollarBuggy
{

  public static void main( String[] args ) 
  {
    double initialAmount = 1000.00 ;
    double dollars = 0.0;
    double rate;
    int    year;

    rate = 0.0;   // Start interest rate at zero
 
    while ( dollars < 1000000 )
    {

       // compute the dollars after 40 years at the current rate
       year =  1 ;     
       dollars = initialAmount;     
       while (  year <= 40 )
       {     
         dollars = dollars + dollars*rate  ; // add another year's interest     
         dollars = dollars + 1000 ;          // add in this year's contribution
         year    =  year + 1 ;
       }

       // change to the next rate
       rate = rate + 0.001;

    }

    System.out.println("After 40 years at " + rate*100 
      + " percent interest you will have " + dollars + " dollars" );
  }

}