How do I limit the number of decimals printed for a double?

double, int, java

Solution

Use a DecimalFormatter:

double number = 0.9999999999999;
DecimalFormat numberFormat = new DecimalFormat("#.00");
System.out.println(numberFormat.format(number));

Will give you "0.99". You can add or subtract 0 on the right side to get more or less decimals.

Or use '#' on the right to make the additional digits optional, as in with #.## (0.30) would drop the trailing 0 to become (0.3).

Problem

This program works, except when the number of nJars is a multiple of 7, I will get an answer like $14.999999999999998. For 6, the output is 14.08. How do I fix exceptions for multiples of 7 so it will display something like $14.99? ``` import java.util.Scanner; public class Homework_17 { private static int nJars, nCartons, totalOunces, OuncesTolbs, lbs; public static void main(String[] args) { computeShippingCost(); } public static void computeShippingCost() { System.out.print("Enter a number of jars: "); Scanner kboard = new Scanner (System.in); nJars = kboard.nextInt(); int nCartons = (nJars + 11) / 12; int totalOunces = (nJars * 21) + (nCartons * 25); int lbs = totalOunces / 16; double shippingCost = ((nCartons * 1.44) + (lbs + 1) * 0.96) + 3.0; System.out.print("$" + shippingCost); } } ```

Original source

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