how to write regex to extract numbers from a string in Java?

Question

For example, I have a set of text "1234568asdjhgsd", I just want to get the number, what should I do? The following is my code, he can't execute it to the while step

    textView.setText("1234568asdjhgsd");

        String str = (String) textView.getText();

        button.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                Pattern p;
                p = Pattern.compile("\\d{10}");
                Matcher m;
                m = p.matcher(str);
                
                while (m.find()){
                    String xxx = m.group();
                    System.out.println(xxx);
                }
            }
        });

It didn't print anything

This will be useful to you https://stackoverflow.com/questions/25015186/how-to-extract-a-number-from-a-string — KGeeks, Sep 16 '21 at 04:26
Thanks, according to your method, I have completed the function I want — Luxira, Sep 16 '21 at 04:39

score 1 · Answer 1 · answered Sep 16 '21 at 04:28

1

p = Pattern.compile("\\d{10}"); this matches 10 digits but your text "1234568asdjhgsd" only has 7 digits. You can use Pattern.compile("\\d{7}"); and it'll work. But number of digits always has to be <= 7.

answered Sep 16 '21 at 04:28

KavG

169
1
12

score 0 · Answer 2 · answered Sep 16 '21 at 04:30

0

print it if matches digits.

  String str = "1234568asdjhgsd"; 
  Pattern p;
  p = Pattern.compile("\\d");
  Matcher m;
  m = p.matcher(str);
        
  while (m.find()){
      String xxx = m.group();
      System.out.print(xxx);
  }

answered Sep 16 '21 at 04:30

chanrlc

182
1
10

score 0 · Answer 3 · answered Sep 16 '21 at 10:50

you can just use java method replaceAll with regex. This will look like this:

String someString = "1234568asdjhgsd";
String replacedString = someString.replaceAll("0-9","");

First argumen of replaceAll means it will accept only digits from 0 to 9, and the second is for what it will be changed

how to write regex to extract numbers from a string in Java?

3 Answers3