The meta character "." matches all the characters, to print all the characters using the regular expressions −Compile the regular expression using the compile() method.Create a Matcher object using the matcher() method.Find the matches using the find() method and for every match print the matched contents (characters) using the group() method.Example Live Demoimport java.util.Scanner; import java.util.regex.Matcher; import java.util.regex.Pattern; public class RegexExample {    public static void main( String args[] ) {       //Regular expression to match a string of non-word with length 2 to 6       String regex = ".";       Scanner sc = new ... Read More

In windows "\r" acts as the line separator. The regular expression "\r?" matches the line endings.The split() method of the String class accepts a value representing a regular expression and splits the current string into array of tokens (words), treating the string between the occurrence of two matches as one token.Therefore, if you want to split a string with line endings as delimiter, invoke the split() method on the input string by passing the above specified regular expression as a parameter.Example Live Demoimport java.util.Scanner; public class RegexExample {    public static void main(String[] args) {       System.out.println("Enter your input ... Read More

The regular expression "[!._, '@?//s]" matches all the punctuation marks and spaces.Exampleimport java.util.Scanner; import java.util.regex.Matcher; import java.util.regex.Pattern; public class Test {    public static void main( String args[] ) {       String input = "This is!a.sample"text, with punctuation!marks";       Pattern p = Pattern.compile("[!._, '@?//s]");       Matcher m = p.matcher(input);       int count = 0;       while(m.find()) {          count++;       }       System.out.println("Number of matches: "+count);    } }OutputNumber of matches: 8The split() method of the String class accepts a value representing a ... Read More

The java.util.regex.MatcheResult interface provides methods to retrieve the results of a matchYou can get an object of this interface using the toMatchResult() method of the Matcher class. This method returns a MatchResult object which represents the match state of the current matcher.The group(int group) method of this interface accepts an integer value representing a particular group and returns a string value representing the matched substring from the given input sequence, in the specified group during the last match.Example Live Demoimport java.util.Scanner; import java.util.regex.MatchResult; import java.util.regex.Matcher; import java.util.regex.Pattern; public class GroupExample {    public static void main( String args[] ) {   ... Read More

This class \p{IsLatin} matches characters of Latin.Example 1 Live Demoimport java.util.Scanner; import java.util.regex.Matcher; import java.util.regex.Pattern; public class Example {    public static void main(String args[]) {       //Reading String from user       System.out.println("Enter a string");       Scanner sc = new Scanner(System.in);       String input = sc.nextLine();       //Regular expression       String regex = "\p{IsLatin}";       //Compiling the regular expression       Pattern pattern = Pattern.compile(regex);       //Retrieving the matcher object       Matcher matcher = pattern.matcher(input);       int count = 0; ... Read More

The replaceAll() method of the List interface accept an object of the UnaryOperator representing a particular operation, performs the specified operation on all the elements of the current list and replaces the existing values in the list with their respective results.Example Live Demoimport java.util.ArrayList; import java.util.function.UnaryOperator; class Op implements UnaryOperator {    public String apply(String str) {       return str.toUpperCase();    } } public class Test {    public static void main(String[] args) throws CloneNotSupportedException {       ArrayList list = new ArrayList();       list.add("Java");       list.add("JavaScript");       list.add("CoffeeScript");       ... Read More

Following regular expression matches given e-mail id including the blank input −^([a-zA-Z0-9._%+-]+@[a-zA-Z0-9.-]+\.[a-zA-Z]{2, 6})?$Where, ^ matches the starting of the sentence.[a-zA-Z0-9._%+-] matches one character from English alphabet (both cases), digits, "+", "_", ".", "" and, "-" before the @ symbol.+ indicates the repetition of the above mentioned set of characters one or more times.@ matches itself[a-zA-Z0-9.-] matches one character from English alphabet (both cases), digits, "." and "-" after the @ symbol\.[a-zA-Z]{2, 6} two to 6 letter for email domain after "."$ indicates the end of the sentenceExample 1 Live Demoimport java.util.Scanner; import java.util.regex.Matcher; import java.util.regex.Pattern; public class SampleTest {    public ... Read More

The java.util.regex.MatcheResult interface provides methods to retrieve the results of a match.You can get an object of this interface using the toMatchResult() method of the Matcher class. This method returns a MatchResult object which represents the match state of the current matcher.The groupCount() method of this interface counts and returns the number of groups in the regular expression of the current object.Example Live Demoimport java.util.Scanner; import java.util.regex.MatchResult; import java.util.regex.Matcher; import java.util.regex.Pattern; public class GroupCount {    public static void main( String args[] ) {       String regex = "(.*)(\d+)(.*)";       //Reading input from user       ... Read More

Greedy quantifiers are the default quantifiers. A greedy quantifier matches as much as possible from the input string (longest match possible) if match not occurred it leaves the last character and matches again. Following is the list of greedy quantifiers −QuantifierDescriptionre*Matches zero or more occurrences.re?Matches zero or, 1 occurrence.re+Matches one or more occurrences.re{n}Matches exactly n occurrences.re{n, }Matches at least n occurrences.re{n, m}Matches at least n and at most m occurrences.ExampleIn the following Java example we are trying to match 1 or more digits, our input string is 45545 though the values 4, 45, 455 etc… are eligible, since we are ... Read More

The regular expression "\S" matches a non-whitespace character and the following regular expression matches one or more non space characters between the bold tags."(\S+)"Therefore to match the bold fields in a HTML script you need to −Compile the above regular expression using the compile() method.Retrieve the matcher from the obtained pattern using the matcher() method.Print the matched parts of the input string using the group() method.Exampleimport java.util.regex.Matcher; import java.util.regex.Pattern; public class Example {    public static void main(String[] args) {      String str = "This is an example>/b> HTML script.";       //Regular expression to match contents of ... Read More