Java中的正则表达式\ b元字符
子表达式/元字符“\b”与方括号外的单词边界匹配。与括号内的空格匹配(0x08)。
例子1
import 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 ++; } System.out.println("Number of matches: "+count); } }
输出结果
Enter a string: A sentence doesn't end with because because, because is a conjunction Number of matches: 3
例子2
以下Java示例从用户读取字符串值,并打印单词边界数。
import java.util.Scanner; import java.util.regex.Matcher; import java.util.regex.Pattern; public class Example { public static void main( String args[] ) { System.out.println("Enter input string: "); Scanner sc = new Scanner(System.in); String input = sc.nextLine(); String regex = "\\b"; //编译正则表达式 Pattern pattern = Pattern.compile(regex); //检索匹配器对象 Matcher matcher = pattern.matcher(input); int count =0; while(matcher.find()) { count ++; } System.out.println(count); } }
输出结果
Enter input string: Hello how are you welcome to Nhooo 14