adding n number of zeros after decimal

Question

I need to give accuracy of a number entered by user till few digit. like if user enter some random value and gives that he wants accuracy till three digit then I need to rou

Answer 1

You can indeed use NumberFormat to do this

double amount = 15;
NumberFormat formatter = new DecimalFormat("#0.000");
System.out.println("The Decimal Value is:"+formatter.format(amount));

Answer 2

you can use string format:

Double area = 6

String ar = String.format("%.3f", area); ar = 6.000

Answer 3

You can create a method that returns the exact format for your decimals. Here is an example:

public String formatNumber(int decimals, double number) {
    StringBuilder sb = new StringBuilder(decimals + 2);
    sb.append("#.");
    for(int i = 0; i < decimals; i++) {
        sb.append("0");
    }
    return new DecimalFormat(sb.toString()).format(number);
}

If you don't need to change the decimals value so often, then you can change your method to something like:

public DecimalFormat getDecimalFormat(int decimals) {
    StringBuilder sb = new StringBuilder(decimals + 2);
    sb.append("#.");
    for(int i = 0; i < decimals; i++) {
        sb.append("0");
    }
    return new DecimalFormat(sb.toString());
}