Java - format double value as dollar amount

Question

I need to format the double "amt" as a dollar amount println("$" + dollars + "." + cents) such that there are two digits after the decimal.

What is the best way to go about doing so?

if (payOrCharge <= 1)
{
    System.out.println("Please enter the payment amount:");
    double amt = keyboard.nextDouble();
    cOne.makePayment(amt);
    System.out.println("-------------------------------");
    System.out.println("The original balance is " + cardBalance + ".");
    System.out.println("You made a payment in the amount of " + amt + ".");
    System.out.println("The new balance is " + (cardBalance - amt) + ".");
}
else if (payOrCharge >= 2)
{
    System.out.println("Please enter the charged amount:");
    double amt = keyboard.nextDouble();
    cOne.addCharge(amt);
    System.out.println("-------------------------------");
    System.out.println("The original balance is $" + cardBalance + ".");
    System.out.println("You added a charge in the amount of " + amt + ".");
    System.out.println("The new balance is " + (cardBalance + amt) + ".");
}

Look at **String.format()**, by the way double is not a good type for keeping currency amounts, use BigDecimal instead. — Amir Pashazadeh, Dec 09 '12 at 20:24
Duplicate? - http://stackoverflow.com/questions/153724/how-to-round-a-number-to-n-decimal-places-in-java — mawaldne, Dec 09 '12 at 20:25

score 66 · Answer 1 · edited Jan 09 '17 at 09:31

66

Use NumberFormat.getCurrencyInstance():

double amt = 123.456;    

NumberFormat formatter = NumberFormat.getCurrencyInstance();
System.out.println(formatter.format(amt));

Output:

$123.46

edited Jan 09 '17 at 09:31

Adeel Ahmad

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answered Dec 09 '12 at 20:23

arshajii

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2

This is the correct answer, you need to import the util though with "import java.text.NumberFormat;" at the top. – Gabriel Pumple Feb 02 '18 at 04:48
2

I had to manipulate it a little to make sure I got the $ sign. NumberFormat.getCurrencyInstance(locale.US) – Anton Apr 19 '18 at 18:00
1

This answer works, till you factor that you did not explicitly set the local. Which is the issue I just came across in my android app, where the user has UK set as their local for a US app (relic code, I did not write). Good to note this pitfall, else you will get incorrect monies values. – StarWind0 Nov 09 '18 at 21:52
If you want to set the locale, you will need to `import java.util.Locale;` as well. Note also that `Locale` is always spelled with a capital "L". – posfan12 Dec 15 '19 at 10:50
How to get it replace 2 decimal places? Or 5? – parsecer May 14 '20 at 01:55

score 9 · Answer 2 · 2012-12-09T21:04:46.450

9

You can use a DecimalFormat

DecimalFormat df = new DecimalFormat("0.00");
System.out.println(df.format(amt));

That will give you a print out with always 2dp.

But really, you should be using BigDecimal for money, because of floating point issues

edited Dec 09 '12 at 21:04

answered Dec 09 '12 at 20:22

score 8 · Answer 3 · edited Dec 11 '15 at 14:38

8

Use DecimalFormat to print a decimal value in desired format e.g.

DecimalFormat dFormat = new DecimalFormat("#.00");
System.out.println("$" + dFormat.format(amt));

If you wish to display $ amount in US number format than try:

DecimalFormat dFormat = new DecimalFormat("####,###,###.00");
System.out.println("$" + dFormat.format(amt));

Using .00, it always prints two decimal points irrespective of their presence. If you want to print decimal only when they are present then use .## in the format string.

edited Dec 11 '15 at 14:38

beresfordt

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answered Dec 09 '12 at 20:23

Yogendra Singh

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_...then use .## in the format string._ - this will show you $5.5 instead of $5.50 – Gaket Dec 16 '16 at 12:35

score 5 · Answer 4 · answered Dec 09 '12 at 20:25

5

You can use printf for a one liner

System.out.printf("The original balance is $%.2f.%n", cardBalance);

This will always print two decimal places, rounding as required.

answered Dec 09 '12 at 20:25

Peter Lawrey

525,659
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1,130

score 1 · Answer 5 · answered Dec 09 '12 at 20:28

1

Use BigDecimal instead of double for currency types. In Java Puzzlers book we see:

System.out.println(2.00 - 1.10);

and you can see it will not be 0.9.

String.format() has patterns for formatting numbers.

answered Dec 09 '12 at 20:28

Amir Pashazadeh

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Java - format double value as dollar amount

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