子表达式/元字符“\b”在括号外匹配单词边界。在括号内匹配退格键 (0x08)。示例 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 ++;   ... 阅读更多

子表达式/元字符“a| b”匹配 a 或 b。示例 1import java.util.regex.Matcher; import java.util.regex.Pattern; public class RegexExample {    public static void main( String args[] ) {       String regex = "Hello|welcome";       String input = "Hello how are you welcome to Tutorialspoint";       Pattern p = Pattern.compile(regex);       Matcher m = p.matcher(input);       int count = 0;       while(m.find()) {          count++;       }       System.out.println("Number of matches: "+count);    } }输出匹配次数：2示例 2以下 Java 程序读取性别 ... 阅读更多

子表达式/元字符“re{ n, m}”匹配至少 n 次，最多 m 次前面的表达式。示例 1import java.util.regex.Matcher; import java.util.regex.Pattern; public class RegexExample {    public static void main( String args[] ) {       String regex = "xyy{2, 4}";       String input = "xxyyzxxyyyyxyyzxxyyzz";       Pattern p = Pattern.compile(regex);       Matcher m = p.matcher(input);       int count = 0;       while(m.find()) {          count++;       }       System.out.println("Number of matches: "+count);    } }输出匹配次数：1示例 2以下 ... 阅读更多

子表达式/元字符“re{ n}”精确匹配前面表达式的 n 次出现。示例 1import java.util.regex.Matcher; import java.util.regex.Pattern; public class RegexExample {    public static void main( String args[] ) {       String regex = "to{1}";       String input = "Welcome to Tutorialspoint";       Pattern p = Pattern.compile(regex);       Matcher m = p.matcher(input);       int count = 0;       while(m.find()) {          count++;       }       System.out.println("Number of matches: "+count);    } }输出匹配次数：2示例 2以下 Java 程序读取年龄 ... 阅读更多

子表达式/元字符“re+”匹配前面表达式的一次或多次出现。示例 1import java.util.regex.Matcher; import java.util.regex.Pattern; public class RegexExample {    public static void main( String args[] ) {       String regex = "aabc+";       String input = "aabcabcaabcabbcaabcbcaabc";       Pattern p = Pattern.compile(regex);       Matcher m = p.matcher(input);       int count = 0;       while(m.find()) {          count++;       }       System.out.println("Number of matches: "+count);    } }输出匹配次数：4示例 2import java.util.Scanner; import java.util.regex.Matcher; import java.util.regex.Pattern; public class Test ... 阅读更多

子表达式/元字符“\Z”匹配整个字符串的结尾，但不包括允许的最终行终止符。示例 1import java.util.regex.Matcher; import java.util.regex.Pattern; public class RegexExample {    public static void main( String args[] ) {       String regex = "Tutorialspoint\z";       String input = "Hi how are you welcome to Tutorialspoint";       Pattern p = Pattern.compile(regex);       Matcher m = p.matcher(input);       int count = 0;       while(m.find()) {          count++;       }       System.out.println("Number of matches: "+count);    } }输出匹配次数：1示例 ... 阅读更多

子表达式/元字符“\z”匹配字符串的结尾。示例 1import java.util.regex.Matcher; import java.util.regex.Pattern; public class RegexExample {    public static void main( String args[] ) {       String regex = "Tutorialspoint\z";       String input = "Hi how are you welcome to Tutorialspoint";       Pattern p = Pattern.compile(regex);       Matcher m = p.matcher(input);       int count = 0;       while(m.find()) {          count++;       }       System.out.println("Number of matches: "+count);    } }输出匹配次数：1示例 2以下 Java 程序验证给定的 ... 阅读更多

子表达式/元字符“\A”匹配整个字符串的开头。示例 1import java.util.regex.Matcher; import java.util.regex.Pattern; public class RegexExample {    public static void main( String args[] ) {       String regex = "\AHi";       String input = "Hi how are you welcome to Tutorialspoint";       Pattern p = Pattern.compile(regex);       Matcher m = p.matcher(input);       int count = 0;       while(m.find()) {          count++;       }       System.out.println("Number of matches: "+count);    } }输出匹配次数：1示例 2以下 Java 程序接受一个 ... 阅读更多

子表达式/元字符“\G”匹配上次匹配结束的位置。示例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 = "\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()) {   ... 阅读更多

子表达式/元字符“\D”匹配非数字。示例 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);    } }输出匹配次数：24示例 2import java.util.Scanner; import java.util.regex.Matcher; import java.util.regex.Pattern; public ... 阅读更多