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The meta character “^” matches the beginning of a particular string i.e. it matches the first character of the string. For example, The expression “^\d” matches the string/line starting with a digit.The expression “^[a-z]” matches the string/line starting with a lower case alphabet.Example 1import 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(); String regex = "^[^a-zA-Z0-9//s].*"; //Compiling the ... Read More
The meta character “$” matches the end of a particular string i.e. it matches the last character of the string. For example, The expression “\d$” matches the string/line ending with a digit.The expression “[a-z]$” matches the string/line ending with a lower case alphabet.Example 1import java.util.Scanner; import java.util.regex.Matcher; import java.util.regex.Pattern; public class Example { public static void main(String args[]) { //Reading String from user System.out.println("Enter a String"); Scanner sc = new Scanner(System.in); String input = sc.nextLine(); String regex = ".*[^a-zA-Z0-9//s]$"; //Compiling the ... Read More
To match a range of characters i.e. to match all the characters between two specified characters in a sequence you can use the character class as [a-z]The expression “[a-zA-Z]” accepts any English alphabet.The expression “[0-9&&[^35]]” accepts numbers except 3 and 5.Example 1import 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(); String regex = "^[a-zA-Z0-9]*$"; //Compiling the regular expression ... Read More
The character classes allow you to accept a single character from a fixed set of characters. For example, The expression “[tmp]” matches the characters t or, m or, p.The expression “[^tp]” matches the characters other than t or, p.Example 1import 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 to match the characters t or, m or, p ... Read More
The meta character “.” in java regular expression matches any character (single) it could be the alphabet, number or, any special character.Example 1import 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 to match any character String regex = "."; //Compiling the regular expression Pattern pattern = Pattern.compile(regex); ... Read More
The subexpression/metacharacter “\t” matches the tab spaces.Example 1import java.util.Scanner; import java.util.regex.Matcher; import java.util.regex.Pattern; public class RegexExample { public static void main( String args[] ) { String regex = "\t"; Scanner sc = new Scanner(System.in); System.out.println("Enter a string: "); String input = sc.nextLine(); Pattern p = Pattern.compile(regex); Matcher m = p.matcher(input); int count = 0; while(m.find()) { count ++; } System.out.println("Number of tab spaces: "+count); ... Read More
The subexpression/metacharacter “\b” matches the word boundaries when outside the brackets. Matches the backspace (0x08) when inside the brackets.Example 1import java.util.Scanner; import java.util.regex.Matcher; import java.util.regex.Pattern; public class RegexExample { public static void main( String args[] ) { String regex = "\bbecause\b"; Scanner sc = new Scanner(System.in); System.out.println("Enter a string: "); String input = sc.nextLine(); Pattern p = Pattern.compile(regex); Matcher m = p.matcher(input); int count = 0; while(m.find()) { count ++; ... Read More
The subexpression/metacharacter “\G” matches the point where the last match finished.Exampleimport java.util.Scanner; import java.util.regex.Matcher; import java.util.regex.Pattern; public class RegexExample { public static void main( String args[] ) { String regex = "\G[0-9]"; Scanner sc = new Scanner(System.in); System.out.println("Enter a string: "); String input = sc.nextLine(); Pattern p = Pattern.compile(regex); Matcher m = p.matcher(input); int count = 0; String digits = ""; System.out.println("Digits in the previous match:"); while(m.find()) { ... Read More
The subexpression/metacharacter “\D” matches the non-digits.Example 1import java.util.regex.Matcher; import java.util.regex.Pattern; public class RegexExample { public static void main( String args[] ) { String regex = "\D"; String input = "This is sample text 12 24 56 89 24"; Pattern p = Pattern.compile(regex); Matcher m = p.matcher(input); int count = 0; while(m.find()) { count++; } System.out.println("Number of matches: "+count); } }OutputNumber of matches: 24Example 2import java.util.Scanner; import java.util.regex.Matcher; import java.util.regex.Pattern; public ... Read More
The subexpression/metacharacter “\d” matches the digits.Example 1import java.util.regex.Matcher; import java.util.regex.Pattern; public class RegexExample { public static void main( String args[] ) { String regex = "\d 24"; String input = "This is sample text 12 24 56 89 24"; Pattern p = Pattern.compile(regex); Matcher m = p.matcher(input); int count = 0; while(m.find()) { count++; } System.out.println("Number of matches: "+count); } }OutputNumber of matches: 2Example 2Following is a Java program that ... Read More