How to remove trailing zeros from a double

Question

For example I need 5.0 to become 5, or 4.3000 to become 4.3.

Solution 1

Use DecimalFormat

  double answer = 5.0;
   DecimalFormat df = new DecimalFormat("###.#");
  System.out.println(df.format(answer));

Solution 2

You should use DecimalFormat("0.#")

---

For 4.3000

Double price = 4.3000;
DecimalFormat format = new DecimalFormat("0.#");
System.out.println(format.format(price));

output is:

4.3

---

In case of 5.000 we have

Double price = 5.000;
DecimalFormat format = new DecimalFormat("0.#");
System.out.println(format.format(price));

And the output is:

5

Solution 3

Use a DecimalFormat object with a format string of "0.#".

Comments

[Peter Elliott]

this fails the case of 5.0 becoming 5, as it will always add a .0 to the end of numbers.

[Marcin Szymczak]

Thank you for Your comment. Now I have figured out that I should have used 0.#.

[David Conrad]

this fails in the case of 4.32 which becomes 4.3

[VikrantY]

Won't this round the numnber like in case of 5.000001

[Mostafa Zeinali]

It does and that's why this is wrong...

[narancs]

this fails in the case of 4.32 which becomes 4.3

[dashrb]

fair point, although the OP didn't indicate how many places were desired. I can't think of a good reason to truncate trailing 0's but keep non-zeros as far as they are printable. IMHO, when printing a double, the code should specify the desired number of digits of precision (the number of #'s after the period).

[Uncle Iroh]

@Karoly DecimalFormat df = new DecimalFormat("###.##"); df.setRoundingMode(RoundingMode.HALF_UP); System.err.println(df.format(4.325)); System.err.println(df.format(4.30)); System.err.println(df.format(4.00));

[Chisko]

@DavidConrad yes, because it is specifying only one decimal digit precision

[David Conrad]

@Chisko The question asks how to "remove trailing zeros".

[Chisko]

But the description clarifies

[Mohit Rajput]

It fails, 4.300001 becomes 4.3 and if you want to convert it to double, it will add .0 again.

[JU5T1C3]

be aware that the output is 4,3 and not 4.3

[Rok Povsic]

A double type can't really do this. If you're willing to switch to BigDecimal, here's the solution.

[fHate]

But how to be with values like 0.0005000 (must shown as 0.0005)?

[Peter Schorn]

@dashrb The OP was very explicit about what he wanted. He wants to remove trailing zeroes. Do you understand what the word "trailing" means?

[Prabhat Gaur]

@UncleIroh FYI this provides correct solution even after removing the RoundingMode.HALF_UP but keeping #.###