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?

Answer 1

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(" ", "")));