如何使用 Java RegEx 匹配一组固定字符
字符类允许你从一个固定的字符集中接受单个字符。例如,
表达式“[tmp]”匹配字符 t 或 m 或 p。
表达式“[^tp]”匹配除 t 或 p 之外的字符。
例 1
import 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 String regex = "[tmp]"; //Compiling the regular expression Pattern pattern = Pattern.compile(regex); //Retrieving the matcher object Matcher matcher = pattern.matcher(input); int count = 0; while(matcher.find()) { count++; } System.out.println("Occurrences: "+count); } }
输出
Enter a String hello how are you welcome to tutorialspoint Occurrences :6
例 2
import 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 = "[^abcdef]"; //Compiling the regular expression Pattern pattern = Pattern.compile(regex); //Retrieving the matcher object Matcher matcher = pattern.matcher(input); int count = 0; while(matcher.find()) { count++; } System.out.println("Occurrences :"+count); } }
输出
Enter a String Hello how are you welcome to tutorialspoint Occurrences :36
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