如何使用Java RegEx匹配一组固定的字符
字符类使您可以接受一组固定字符中的单个字符。例如，
表达式“[tmp]”与字符t或m或p匹配。
表达式“[^tp]”与t或p之外的其他字符匹配。
例子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);
}
}输出结果
Enter a String hello how are you welcome to tutorialspoint Occurrences :6
例子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);
}
}输出结果
Enter a String Hello how are you welcome to tutorialspoint Occurrences :36