How to Convert String value into Double or Int value in Java?

Question

I have a problem. I have String with the value "$615.00" and I want to convert it to double or int. I have tried the following code but there is an error:

String one = "$615.00";
String two = "$15.00";
double newone = Double.parseDouble( one );
double newtwo = Double.parseDouble( two );

System.out.println(newone-newtwo);

The error is

Exception in thread "main" java.lang.NumberFormatException: For input string: "$615.00"

But I have added the NumberFormatException for the method and still got the error.

Does this answer your question? [Convert String to double in Java](https://stackoverflow.com/questions/5769669/convert-string-to-double-in-java) You are correct... however the $ cannot be used. I recommend you remove the $ before doing the conversion — D. Lawrence, Dec 11 '19 at 13:40
Without specifying further, my guess is that `Double#parseDouble(String)` can't handle the `'$'` character. Remove that from the string when you pass it in — Frontear, Dec 11 '19 at 13:42
What do you mean by *I have added the NumberFormatException*? you don't catch it anywhere. — Guy, Dec 11 '19 at 13:42
You have them as `String` and you need to remove the currency symbol... Consider using a `BigDecimal`, which takes a `String` in a parameterized constructor and is able to provide a `doubleValue()`. — deHaar, Dec 11 '19 at 13:42
There are some answers to your question posted here. Let us know, if they helped you — Steyrix, Dec 11 '19 at 14:19

score 2 · Accepted Answer · answered Dec 11 '19 at 13:59

2

As others have said in the comments, NumberFormatException is happening because you are trying to parseDouble without removing the $ from the number.

In this case, you can use substring() to get everything after the first char:

String one = "$615.00";
String two = "$15.00";

double newone = Double.parseDouble( one.substring(1) );
double newtwo = Double.parseDouble( two.substring(1) );

System.out.println(newone-newtwo);

Results in 600.00

answered Dec 11 '19 at 13:59

João

449
4
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And what if there will be spaces, digits or other symbols (more than one and on another positions)? For me this is very hardcoded solution – Steyrix Dec 11 '19 at 14:06
Then you'd need a more complex solution, but for any prefixes or sufixes you need to remove, this works – João Dec 11 '19 at 14:10
If the dollar symbol will be a suffix, or there will be 2 options for its position, you will need to change the code and add additional checkings. In other words excess code. This is a major drawback of the solution. You need to write the code in a way, that will provide robust solution with possible changing input data formats – Steyrix Dec 11 '19 at 14:15
I agree, your answer with the regular expression is more complete, but I though a simpler solution could help better in this case, since regular expressions are kinda tricky – João Dec 11 '19 at 14:23
1

Well, assuming the author of question is a beginner, it might be easier and more convenient for him to use your solution. So you do have a point and your answer makes sense :) – Steyrix Dec 11 '19 at 14:25

score 1 · Answer 2 · answered Dec 11 '19 at 15:09

$ is a currency designator. It is not part of a numeric value.

If you have a currency value, you should use a currency format to read it:

NumberFormat format = NumberFormat.getCurrencyInstance();
double newone = format.parse(one).doubleValue();
double newtwo = format.parse(two).doubleValue();

If you are not running on a computer configured for the US, you may need to pass a Locale, to force the currency instance to use US dollars:

NumberFormat format = NumberFormat.getCurrencyInstance(Locale.US);
double newone = format.parse(one).doubleValue();
double newtwo = format.parse(two).doubleValue();

Steyrix · Answer 3 · 2019-12-11T13:56:20.633

0

Use regular expression to remove symbols like "$" (in other words, all symbols but digits and dot)

String one = "$615.03";
String oneValue = one.replaceAll("[^0-9.]", "");
System.out.println(oneValue); // Output is 615.03, which is correctly parsed by parseDobule()

edited Dec 11 '19 at 13:56

answered Dec 11 '19 at 13:48

Steyrix

2,796
1
9
23

Using a regular expression is overkill. Regular expressions are heavyweight, and hard to read and debug. They should not be used unless they are truly needed. – VGR Dec 11 '19 at 14:56
@VGR I don't think that debugging and reading `if-else` statements is easier than reading the single line with pattern. Also, just a single possibility of input data becoming "615.00$" makes it easier to use regex. I would like to know about a better solution for preprocessing strings, since I got voted down – Steyrix Dec 11 '19 at 15:01

How to Convert String value into Double or Int value in Java?

3 Answers3