CODEWITHSUNDEEP
javaarraysregexstring
user1051505
user1051505

Reputation: 962

Extracting numbers into a string array

I have a string which is of the form 

String str = "124333 is the otp of candidate number 9912111242. 
         Please refer txn id 12323335465645 while referring blah blah.";

I need 124333, 9912111242 and 12323335465645 in a string array. I have tried this with 

while (Character.isDigit(sms.charAt(i)))

I feel that running the above said method on every character is inefficient. Is there a way I can get a string array of all the numbers?

Upvotes: 2

Views: 397

Answers (6)

bunyaCloven
bunyaCloven

Reputation: 313

First thing comes into my mind is filter and split, then i realized that it can be done via

String[] result =str.split("\\D+");

\D matches any non-digit character, + says that one or more of these are needed, and leading \ escapes the other \ since \D would be parsed as 'escape character D' which is invalid

Upvotes: 1

Avinash Raj
Avinash Raj

Reputation: 174696

And this works perfectly for your input.

String str = "124333 is the otp of candidate number 9912111242. Please refer txn id 12323335465645 while referring blah blah.";
System.out.println(Arrays.toString(str.split("\\D+")));

Output:

[124333, 9912111242, 12323335465645]

\\D+ Matches one or more non-digit characters. Splitting the input according to one or more non-digit characters will give you the desired output.

Upvotes: 4

Maroun
Maroun

Reputation: 95948

Use a regex (see Pattern and matcher):

Pattern p = Pattern.compile("\\d+");
Matcher m = p.matcher(<your string here>);
while (m.find()) {
    //m.group() contains the digits you want
}

you can easily build ArrayList that contains each matched group you find.

Or, as other suggested, you can split on non-digits characters (\D):

"blabla 123 blabla 345".split("\\D+")

Note that \ has to be escaped in Java, hence the need of \\.

Upvotes: 9

user2336315
user2336315

Reputation: 16067

Java 8 style:

long[] numbers = Pattern.compile("\\D+")
                        .splitAsStream(str)
                        .mapToLong(Long::parseLong)
                        .toArray();

Ah if you only need a String array, then you can just use String.split as the other answers suggests.

Upvotes: 3

Florent Bayle
Florent Bayle

Reputation: 11890

You can use String.split():

String[] nbs = str.split("[^0-9]+");

This will split the String on any group of non-numbers digits.

Upvotes: 4

Stephan
Stephan

Reputation: 43013

Alternatively, you can try this:

String str = "124333 is the otp of candidate number 9912111242. Please refer txn id 12323335465645 while referring blah blah.";

str = str.replaceAll("\\D+", ",");
    
System.out.println(Arrays.asList(str.split(",")));

\\D+ matches one or more non digits

Output

[124333, 9912111242, 12323335465645]

Upvotes: 1

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