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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