如何使用 Java 正则表达式 (RegEx) 匹配非数字
可使用元字符“\D"匹配非数字字符。
示例 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(); String regex = "\D"; //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("Number non-digit characters: "+count); } }
输出
Enter a String sample text 2425 36 Number non-digit characters: 13
示例 2
import java.util.Scanner; public class RegexExample { public static void main( String args[] ) { //regular expression to accept 5 letter word 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
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