Question

I need percentage form of a double value, so I used NumberFormat

    double d = 0.13;   
    NumberFormat nf = NumberFormat.getPercentInstance();      
    String kpr = nf.format(kpr);  

I saved this property to an object Person through setter. When I get it back through getter method it returns String(of course).
Is there a way to de-format this String to double value as 0.13, so that I can perform arithmetics on it?

Answer 1

public static void main(String s[]) {
    getDoubleFromStringWithPercent("12345%");
}

private static Double getDoubleFromStringWithPercent(String string) {
    Locale locale = Locale.CANADA;
    Double num = null;
    try {
        Number number = NumberFormat.getPercentInstance(locale).parse(string);
        if (number instanceof Long) {
            num = ((Long) number).doubleValue();
        } else {
            num = (Double) number;

        }
    } catch (ParseException e) {
        throw new RuntimeException(e);
    }
    return num;
}

Locale need for find decimal delimiter (“.” or “,”);

Alternative version:

String string ="2165%";

double d = Double.parseDouble(string.substring(0, string.length()-1));
if (d != 0) {
   d = d / 100;
}