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Page 498 of 589
How to extract numbers from a string using regular expressions?
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 MoreHow to replace multiple spaces in a string using a single space using Java regex?
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 MoreHow to extract each (English) word from a string using regular expression in Java?
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 MoreProgram to check valid mobile number using Java regular expressions
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 MoreJava Regular expression to check if a string contains alphabet
Following is the regular expression to match alphabet in the given input −"^[a-zA-Z]*$"Where,^ matches the starting of the sentence.[a-zA-z] matches the lower case and upper case letters.* indicates the occurrence for zero or more times.& indicates the end of the line.Example 1import java.util.Scanner; import java.util.regex.Matcher; import java.util.regex.Pattern; public class ContainsAlphabetExample { public static void main(String[] args) { Scanner sc = new Scanner(System.in); String names[] = new String[5]; for(int i=0; i
Read MoreProgram to find whether a string is alphanumeric.
Any word that contains numbers and letters is known as alphanumeric. The following regular expression matches the combination of numbers and letters."^[a-zA-Z0-9]+$";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 MoreHow to remove consonants from a string using regular expressions in Java?
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 MoreProgram to match vowels in a string using regular expression in Java
You can group all the required characters to match within the square braces “[ ]” i.e. The metacharacter/sub-expression “[ ]” matches all the specified characters. Therefore, to match all the letters specify the vowel letters within these as shown below −[aeiouAEIOU]Example 1import java.util.Scanner; import java.util.regex.Matcher; import java.util.regex.Pattern; public class MatchVowels { public static void main( String args[] ) { String regex = "[aeiouAEIOU]"; System.out.println("Enter input string: "); Scanner sc = new Scanner(System.in); String input = sc.nextLine(); //Compiling the regular expression Pattern.compile(regex); ...
Read MoreMoving all Upper case letters to the end of the String using Java RegEx
The subexpression “[ ]” matches all the characters specified in the braces. Therefore, to move all the upper case letters to the end of a string −Iterate through all the characters in the given string.Match all the upper case letters in the given string using the regular expression "[A-Z]".Concatenate the special characters and the remaining characters to two different strings.Finally, concatenate the special characters string to the other string.Example 1public class RemovingSpecialCharacters { public static void main(String args[]) { String input = "sample B text C with G upper case LM characters in between"; ...
Read MoreMoving all special char to the end of the String using Java Regular Expression RegEx)
The following regular expression matches all the special characters i.e. all characters except English alphabet spaces and digits."[^a-zA-Z0-9\s+]"To move all the special characters to the end of the given line, match all the special characters using this regex concatenate them to an empty string and concatenate remaining characters to another string finally, concatenate these two strings.Example 1public class RemovingSpecialCharacters { public static void main(String args[]) { String input = "sample # text * with & special@ characters"; String regex = "[^a-zA-Z0-9\s+]"; String specialChars = ""; String inputData ...
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