CODEWITHSUNDEEP
javaregex
Raj
Raj

Reputation: 1148

Finding numbers in a text and summing them

Seeking regex experts here. I have a string that has numbers in it such as 

abc 2 de fdfg 3 4 fdfdfv juk  @  dfdfgd 45

I need to find all the numbers from such string and sum it up.

My Java code is as follows:

public static void main(String[] args) {

    String source = " abc 2 de fdfg 3 4 fdfdfv juk  @  dfdfgd 45";

    Pattern pattern = Pattern.compile("[\\w*\\W*(\\d*)]+");
    Matcher matcher = pattern.matcher(source);

    if (matcher.matches()) {
        System.out.println("Matched");

            // For loop is not executed since groupCount is zero
            for (int i=0; i<matcher.groupCount(); i++) {
                String group = matcher.group(i);
                System.out.println(group);
            }
    } else {
        System.out.println("Didn't match");
    }
}

So matcher.matches() returns true, and therefore I can see that "Matched" getting printed. However, when I try to get the groups, expecting numbers, nothing gets printed.

Can someone please point to me what is wrong with my regex and grouping part?

Upvotes: 0

Views: 129

Answers (2)

Zesty Memes
Zesty Memes

Reputation: 442

String[] arr=source.split("\\d+");
int sum=0;
for(String x : arr) {
  int n=0;
  try {
    n=Integer.parseInt(x);
  } catch(NumberFormatException nfe){}
  sum+=n;
}

System.out.println("Sum: "+sum);

Upvotes: -1

Shar1er80
Shar1er80

Reputation: 9041

Just extract the digits out in groups and not worry about the white spaces.

public static void main(String[] args) throws Exception {
    String source = " abc 2 de fdfg 3 4 fdfdfv juk  @  dfdfgd 45";

    // "\\d+" will get all of the digits in the String
    Pattern pattern = Pattern.compile("\\d+");
    Matcher matcher = pattern.matcher(source);

    int sum = 0;
    // Convert each find to an Integer and accumulate the total
    while (matcher.find()) {
        sum += Integer.parseInt(matcher.group());
    }
    System.out.println("Sum: " + sum);
}

Results:

Sum: 54

Upvotes: 2

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