Programming Articles - Page 2298 of 3366

You can match numbers in the given string using either of the following regular expressions −“\d+” Or, "([0-9]+)"Example 1import java.util.Scanner; import java.util.regex.Matcher; import java.util.regex.Pattern; public class ExtractingDigits {    public static void main(String[] args) {       Scanner sc = new Scanner(System.in);       System.out.println("Enter sample text: ");       String data = sc.nextLine();       //Regular expression to match digits in a string       String regex = "\d+";       //Creating a pattern object       Pattern pattern = Pattern.compile(regex);       //Creating a Matcher object       Matcher ... Read More

The metacharacter “\s” matches spaces and + indicates the occurrence of the spaces one or more times, therefore, the regular expression \S+ matches all the space characters (single or multiple). Therefore, to replace multiple spaces with a single space.Match the input string with the above regular expression and replace the results with single space “ ”.Example 1import java.util.Scanner; import java.util.regex.Matcher; import java.util.regex.Pattern; public class ReplaceAllExample {    public static void main(String args[]) {       //Reading String from user       System.out.println("Enter a String");       Scanner sc = new Scanner(System.in);       String input = ... Read More

The regular expression “[a-zA-Z]+” matches one or the English alphabet. Therefore, to extract each word in the given input string −Compile the above expression of the compile() method of the Pattern class.Get the Matcher object bypassing the required input string as a parameter to the matcher() method of the Pattern class.Finally, for each match get the matched characters by invoking the group() method.Exampleimport java.util.Scanner; import java.util.regex.Matcher; import java.util.regex.Pattern; public class EachWordExample {    public static void main(String[] args) {       Scanner sc = new Scanner(System.in);       System.out.println("Enter sample text: ");       String data = ... Read More

To verify whether a given input string is a valid e-mail id match it with the following is the regular expression to match an e-mail id −"^[a-zA-Z0-9+_.-]+@[a-zA-Z0-9.-]+$"Where, ^ matches the starting of the sentence.[a-zA-Z0-9+_.-] matches one character from the English alphabet (both cases), digits, "+", "_", "." and, "-" before the @ symbol.+ indicates the repetition of the above-mentioned set of characters one or more times.@ matches itself.[a-zA-Z0-9.-] matches one character from the English alphabet (both cases), digits, "." and "–" after the @ symbol.$ indicates the end of the sentence.Exampleimport java.util.Scanner; public class ValidatingEmail {    public static void ... Read More

You can match a valid mobile number using the following regular expression −"\d{10}"A valid mobile number generally have 10 digits (in India).The metacharacter "\d" matches the digits from 0 to 9.The quantifier ex{n} suggests the repetition of ex n times.Example 1import java.util.Scanner; import java.util.regex.Matcher; import java.util.regex.Pattern; public class PhoneNumberExample {    public static void main(String[] args) {       Scanner sc = new Scanner(System.in);       System.out.println("Enter your name: ");       String name = sc.nextLine();       System.out.println("Enter your Phone number: ");       String phone = sc.next();       //Regular expression to ... Read More

Following is the regular expression to match alphabet in the given input −"^[a-zA-Z]*$"Where,^ matches the starting of the sentence.[a-zA-z] matches the lower case and upper case letters.* indicates the occurrence for zero or more times.& indicates the end of the line.Example 1import java.util.Scanner; import java.util.regex.Matcher; import java.util.regex.Pattern; public class ContainsAlphabetExample {    public static void main(String[] args) {       Scanner sc = new Scanner(System.in);       String names[] = new String[5];       for(int i=0; i

The regular expression “\s” matches the spaces in a string. The replaceAll() method accepts a string and a regular expression replaces the matched characters with the given string. To remove all the white spaces from an input string, invoke the replaceAll() method on it bypassing the above mentioned regular expression and an empty string as inputs.Example 1public class RemovingWhiteSpaces {    public static void main( String args[] ) {       String input = "Hi welcome to tutorialspoint";       String regex = "\s";       String result = input.replaceAll(regex, "");       System.out.println("Result: "+result);   ... Read More

Any word that contains numbers and letters is known as alphanumeric. The following regular expression matches the combination of numbers and letters."^[a-zA-Z0-9]+$";The matches method of the String class accepts a regular expression (in the form of a String) and matches it with the current string in case the match this method returns true else it returns false.Therefore, to find whether a particular string contains alpha-numeric values −Get the string.Invoke the match method on it bypassing the above mentioned regular expression.Retrieve the result.Example 1import java.util.Scanner; public class AlphanumericString {    public static void main(String args[]) {       Scanner sc ... Read More

The simple character class “[ ]” matches all the specified characters in it. The following expression matches the characters except for xyz."[xyz]"Similarly, the following expression matches all the vowels in the given input string."([^aeiouAEIOU0-9\W]+)";Then you can remove the matched characters by replacing them with the empty string “”, using the replaceAll() method.Example 1public class RemovingVowels {    public static void main( String args[] ) {       String input = "Hi welcome to tutorialspoint";       String regex = "[aeiouAEIOU]";       String result = input.replaceAll(regex, "");       System.out.println("Result: "+result);    } }OutputResult: H wlcm ... Read More

The simple character class “[ ]” matches all the specified characters in it. The meta character ^ acts as negation within the above character class i.e. the following expression matches all the characters except b (including spaces and special characters)"[^b]"Similarly, the following expression matches all the consonants in the given input string."([^aeiouyAEIOUY0-9\W]+)";Then you can remove the matched characters by replacing them with the empty string “”, using the replaceAll() method.Example 1public class RemovingConstants {    public static void main( String args[] ) {       String input = "Hi welc#ome to t$utori$alspoint";       String regex = "([^aeiouAEIOU0-9\W]+)"; ... Read More