Parsing a number from a string with thousands seperators

Question

i'm parsing out Long values from given String-s.

Long.valueOf() and Long.parseLong() wouldn't work - because such a String str is in the format 1,234,567 and can be surrounded by spaces.

I can work this by processing the String to get it to bare digits-- then parsing the value out. so - it would be something like

str.trim(); 
String tempArray [] = str.split(","); 
str = ""; 
for (String s:tempArray)
    str+=s;

however, there must be a better way of doing this. What is it?

Rohit Jain · Accepted Answer · 2015-03-16T15:22:01.263

You can use NumberFormat here, with appropriate Locale. US locale would suffice here. You've to take care of whitespaces though.

String str = "1,234,567";
NumberFormat format = NumberFormat.getInstance(Locale.US);
System.out.println(format.parse(str.replace(" ", "")));

You can even use DecimalFormat which is slightly more powerful. You can add any grouping or decimal separator:

DecimalFormat decimalFormat = new DecimalFormat();
DecimalFormatSymbols decimalFormatSymbols = new DecimalFormatSymbols();
decimalFormatSymbols.setGroupingSeparator(',');
decimalFormat.setDecimalFormatSymbols(decimalFormatSymbols);

System.out.println(decimalFormat.parse(str.replace(" ", "")));

score 4 · Answer 2 · answered Mar 16 '15 at 15:14

4

Of course it is possible :)

String newStr = str.replaceAll(",","");

For removing even spaces :

String newStr = str.replaceAll(",","").replaceAll(" ","");

And you can pass it to Long immediately

Long myLong = Long.valueOf(str.replaceAll(",","").replaceAll(" ",""));

answered Mar 16 '15 at 15:14

libik

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might need to remove whitespace too since it "can be surrounded by spaces". – barbiepylon Mar 16 '15 at 15:16
oops...I think I must've seen an early version of your answer! Looks good! – barbiepylon Mar 16 '15 at 15:19
i like this - w/one note: str.replaceAll(",| ","") saves another iteration on str – user4402742 Mar 16 '15 at 15:21
1

As the first string in replaceAll is a regexp, you can use something like "[, ]" to avoid the second replaceAll call. – Ulf Jaehrig Mar 16 '15 at 15:24

score 4 · Answer 3 · answered Mar 16 '15 at 15:18

4

The replaceAll method can remove your commas and trim removes white space:

Long.parseLong(str.trim().replaceAll(",", ""))

answered Mar 16 '15 at 15:18

Neil Masson

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trim only removes leading and trailing whitespace – barbiepylon Mar 16 '15 at 15:33
@BarbiePylon The question says that the string can be "surrounded by spaces", so `trim` is appropriate here. – Neil Masson Mar 16 '15 at 15:36
I didn't take it so literally like that, but I suppose you've got a point! – barbiepylon Mar 16 '15 at 15:37

Parsing a number from a string with thousands seperators

3 Answers3