How to Extract the Numerical value from a String

Question

Im building an android application in which i want to extract only the numeric values(Rs.875) from the inbox message and add them all. how can i do it please give some ideas.

example:The messages will be like this- 1> Recharge of Rs.196 for 9055668800 is successful. Recharge prepaid mobile instantly using freecharge app. 2>hi, we have received payment of Rs.2000.00 with ref.no.NF789465132. Stay tuned while we confirm your booking.

I have to calculate only the amount in from the text.

Answer 1

You can do it like this: You can use Regex like "(?<=Rs.)\\\\d+[\\\\.\\\\d]*" to get only the amount as asked in the question. I have to calculate only the amount in from the text.

String message = "Recharge of Rs.196 for 9055668800 is successful. Recharge prepaid mobile instantly using freecharge app. hi, we have received payment of Rs.2000.00 with ref.no.NF789465132. Stay tuned while we confirm your booking.";
Pattern pattern = Pattern.compile("(?<=Rs.)\\d+[\\.\\d]*");
Matcher matcher = pattern.matcher(message);
double sum = 0;
while (matcher.find()) {
    String digit = matcher.group();
    System.out.println("digit = " + digit);
    sum += Double.parseDouble(digit);
}
System.out.println("sum = " + sum);

And it is the out put:

digit = 196
digit = 2000.00
sum = 2196.0

Answer 2

Here's one without regex:

String[] messageParts = message.split(" ");
double sum = 0;

for (String messagePart : messageParts) {
    if (messagePart.startsWith("Rs.")) {
        sum += Double.parseDouble(messagePart.substring(messagePart.indexOf("Rs.") + 3));
    }
}
System.out.println("Sum: " + sum);

And the output is

Sum: 2196.0

Answer 3

If you want to extract only the recharge amount from the given String then you can use a Regex like Rs.[0-9.]+ . You can then parse it to Integer or Double to sum it up.

Here is a quick code snippet:

public static void main (String[] args)
{
    String str = "Recharge of Rs.196.00 for 9055668800 is successful.";
    Pattern r = Pattern.compile("Rs.[0-9.]+");
    Matcher m = r.matcher(str);
    double sumTotal = 0;
    if (m.find()) {
       System.out.println("Amount: " + m.group(0).substring(3));
       sumTotal += Double.parseDouble(m.group(0).substring(3));
    }
}

Output:

Amount: 196.00