Parse String into Number

Question

I have a list which will store Number objects. The list will be populated by parsing a list of strings, where each string may represent any subclass of Number.

How do I parse a string to a generic number, rather than something specific like an integer or float?

Answer 1

Number cannot be instantiated because it is an abstract class. I would recommend passing in Numbers, but if you are set on Strings you can parse them using any of the subclasses,

Number num = Integer.parseInt(myString);

or

Number num = NumberFormat.getInstance().parse(myNumber);

@See NumberFormat

Answer 2

You can use the java.text.NumberFormat class. This class has a parse() method which parses given string and returns the appropriate Number objects.

        public static void main(String args[]){
            List<String> myStrings = new ArrayList<String>(); 
            myStrings.add("11");
            myStrings.add("102.23");
            myStrings.add("22.34");

            NumberFormat nf = NumberFormat.getInstance();
            for( String text : myStrings){
               try {
                    System.out.println( nf.parse(text).getClass().getName() );
               } catch (ParseException e) {
                    e.printStackTrace();
               }
           }
        }