用示例对Java中的toString()方法进行模式化
java.util.regex包的Pattern类是正则表达式的编译表示。
此类的toString()方法返回用于编译当前Pattern的正则表达式的字符串表示形式。
例1
import java.util.Scanner;
import java.util.regex.Pattern;
public class Example {
public static void main( String args[] ) {
//读取字符串值
Scanner sc = new Scanner(System.in);
System.out.println("Enter input string");
String input = sc.nextLine();
//查找数字的正则表达式
String regex = "(\\d)";
//编译正则表达式
Pattern pattern = Pattern.compile(regex);
//打印正则表达式
System.out.println("Compiled regular expression: "+pattern.toString());
//验证是否发生匹配
if(pattern.matcher(input).find())
System.out.println("Given String contains digits");
else
System.out.println("Given String does not contain digits");
}
}输出结果
Enter input string This 7est contain5 di9its in place of certain charac7er5 Compiled regular expression: (\d) Given String contains digits
例子2
import java.util.regex.Pattern;
public class Example {
public static void main(String args[]) {
String regex = "Nhooo$";
String input = "Hi how are you welcome to Nhooo";
Pattern pattern = Pattern.compile(regex);
Matcher match = pattern.matcher(input);
int count = 0;
if(match.find())
System.out.println("Match found");
else
System.out.println("Match not found");
System.out.println("regular expression: "+pattern.toString());
}
}输出结果
Match found regular expression: Nhooo$