你可以使用预编译的
图案
和
匹配器
,或通过不带regex的子字符串。
import java.util.regex.Pattern;
import java.util.regex.Matcher;
public class Main {
public static void main(String[] args) {
String input = "123456789";
// Approach 1: Using precompiled Pattern and Matcher
Pattern pattern = Pattern.compile("(\\d{3})(\\d{2})(\\d{4})");
Matcher matcher = pattern.matcher(input);
String ssnFormattedPattern = matcher.replaceAll("$1-$2-$3");
System.out.println("Using Pattern and Matcher: " + ssnFormattedPattern);
// Approach 2: Using substring without regex
String ssnFormattedSubstring = input.substring(0, 3) + "-" + input.substring(3, 5) + "-" + input.substring(5);
System.out.println("Using substring: " + ssnFormattedSubstring);
}
}