如何使用Java正则表达式(RegEx)匹配非数字
您可以使用元字符“\\D”匹配非数字字符。
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[]) { //从用户读取字符串 System.out.println("Enter a String"); Scanner sc = new Scanner(System.in); String input = sc.nextLine(); String regex = "\\D"; //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("Number non-digit characters: "+count); } }
输出结果
Enter a String sample text 2425 36 Number non-digit characters: 13
例子2
import java.util.Scanner; public class RegexExample { public static void main( String args[] ) { //正则表达式接受5个字母的单词 String regex = "\\D{10}"; System.out.println("Enter input value: "); Scanner sc = new Scanner(System.in); String input = sc.nextLine(); boolean result = input.matches(regex); if(result) { System.out.println("input matched"); } else { System.out.println("wrong input"); } } }
输出1
Enter input value: sample abc input matched
输出2
Enter input value: sample1234 wrong input