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Hi I am trying to build one regex to extract 4 digit number from given string using java. I tried it in following ways:
String mydata = "get the 0025 data from string";
Pattern pattern = Pattern.compile("^[0-9]+$");
//Pattern pattern = Pattern.compile("^[0-90-90-90-9]+$");
//Pattern pattern = Pattern.compile("^[\\d]+$");
//Pattern pattern = Pattern.compile("^[\\d\\d\\d\\d]+$");
Matcher matcher = pattern.matcher(mydata);
String val = "";
if (matcher.find()) {
System.out.println(matcher.group(1));
val = matcher.group(1);
}
But it's not working properly. How to do this. Need some help. Thank you.
510
Add the $ anchor. /^SW\d{4}$/ . It's because of the \w+ where \w+ match one or more alphanumeric characters. \w+ matches digits as well.
String pin = obj. nextLine(); To check if this pin contains 4 digits, we can use the regex \d{4} .
\d (digit) matches any single digit (same as [0-9] ). The uppercase counterpart \D (non-digit) matches any single character that is not a digit (same as [^0-9] ).
How to extract numbers from a string using regex in Java? Extracting all numeric data from the string content is a very common and useful scenerio and can be achieved using a regex pattern. The basic pattern we need to use is a “ [0-9]”, i.e. character class of digits from 0 to 9.
Java Regex. The Java Regex or Regular Expression is an API to define a pattern for searching or manipulating strings. It is widely used to define the constraint on strings such as password and email validation. After learning Java regex tutorial, you will be able to test your regular expressions by the Java Regex Tester Tool.
It is widely used to define the constraint on strings such as password and email validation. After learning Java regex tutorial, you will be able to test your regular expressions by the Java Regex Tester Tool.
You can go with \d {4} or [0-9] {4} but note that by specifying the ^ at the beginning of regex and $ at the end you're limiting yourself to strings that contain only 4 digits. My recomendation: Learn some regex basics. Show activity on this post.
Change you pattern to:
Pattern pattern = Pattern.compile("(\\d{4})");
\d is for a digit and the number in {} is the number of digits you want to have.
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