Java中的正则表达式“ \ d”构造
子表达式/元字符“\d”与数字匹配。
例子1
import java.util.regex.Matcher;
import java.util.regex.Pattern;
public class RegexExample {
public static void main( String args[] ) {
String regex = "\\d 24";
String input = "This is sample text 12 24 56 89 24";
Pattern p = Pattern.compile(regex);
Matcher m = p.matcher(input);
int count = 0;
while(m.find()) {
count++;
}
System.out.println("Number of matches: "+count);
}
}输出结果
Number of matches: 2
例子2
以下是一个从用户读取10位数字的Java程序。
import java.util.Scanner;
import java.util.regex.Matcher;
import java.util.regex.Pattern;
public class Test {
public static void main( String args[] ) {
String regex = "\\d{10}";
Scanner sc = new Scanner(System.in);
System.out.println("Enter your phone number (10 digits): ");
String input = sc.nextLine();
//创建一个Pattern对象
Pattern p = Pattern.compile(regex);
//创建一个Matcher对象
Matcher m = p.matcher(input);
if(m.find()) {
System.out.println("OK");
} else {
System.out.println("Wrong input");
}
}
}输出1
Enter your phone number (10 digits): 9848022338 OK
输出2
Enter your phone number (10 digits): 545 Wrong input