Java: variable decimal length formatted output

Question

Let a be any floating point number:

float a = 13.1234567;

then I get a decimal places length from standard input:

import java.util.Scanner;
Scanner sc = new Scanner(System.in);
int decLen = sc.nextInt();

How do I print 'a' with 'decLen' decimal places after the point? I need to print for

decLen = 3:

13.123

decLen = 6:

13.123456

decLen = 0:

Is there in the Java libaries any formatting method capable of this kind of tasks?

It is not a duplicate. This question deals with the scale of a primitive and the other formatting a number to a given scale. — user6629913, Feb 21 '18 at 16:03

user6629913 · Answer 1 · 2018-02-21T16:23:34.110

-1

A bit of a hack, but this will work:

    double[] doubles = {13.123, 13.123456, 13};
    for (int i = 0; i < doubles.length; i++) {
        BigDecimal bigDecimal = new BigDecimal(String.valueOf(doubles[i]));
        System.out.println("decLen = " + bigDecimal.stripTrailingZeros().scale());
    };

prints:

decLen = 3
decLen = 6
decLen = 0

Converting the float or double to a string will prevent rounding errors when creating the BigDecimal.

edited Feb 21 '18 at 16:23

answered Feb 21 '18 at 15:50

user6629913

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This is not answering _"How do I print 'a' with 'decLen' decimal places after the point?"_ – Juan Carlos Mendoza Feb 21 '18 at 18:34

Java: variable decimal length formatted output

1 Answers1