Yes. The job of the outer loop is to pick a higher rate each time the inner loop is started.
Notice how rate
keeps increasing, but dollars
is reset to initialAmount
for every new set of 40 years.
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" ); } }
Is there a bug in this program?