Java中的Matcher regionStart()方法与示例
java.util.regex.Matcher类表示执行各种匹配操作的引擎。该类没有构造函数，可以使用类java.util.regex.Pattern的matchs()方法创建/获取该类的对象。
这个(Matcher)类的regionStart()方法返回一个整数值，该整数值表示当前匹配器对象的起始索引。
例子1
import java.util.Scanner;
import java.util.regex.Matcher;
import java.util.regex.Pattern;
public class RegionStartExample {
public static void main(String[] args) {
//Regular expression to accepts 6 to 10 characters
String regex = "[#]";
System.out.println("Enter a string: ");
Scanner sc = new Scanner(System.in);
String input = sc.nextLine();
//Creating a pattern object
Pattern pattern = Pattern.compile(regex);
//Creating a Matcher object
Matcher matcher = pattern.matcher(input);
//Setting region to the input string matcher.region(2, 4);
//Switching to transparent bounds
if(matcher.find()) {
System.out.println("Match found");
} else {
System.out.println("Match not found");
}
System.out.println("Starting of the region: "+ matcher.regionStart());
}
}输出结果
Enter a string: #sample text Match not found Starting of the region: 2
例子2
import java.util.regex.Matcher;
import java.util.regex.Pattern;
public class RegionStartExample {
public static void main(String[] args) {
String regex = "(.*)(\\d+)(.*)";
String input = "124 This is a sample Text, 1234, with numbers in between.";
//Creating a pattern object
Pattern pattern = Pattern.compile(regex);
//Creating a Matcher object
Matcher matcher = pattern.matcher(input);
//Setting the region of the matcher
matcher.region(5, 20);
if(matcher.matches()) {
System.out.println("Match found");
} else {
System.out.println("Match not found");
}
System.out.print("Start of the region: "+matcher.regionStart());
}
}输出结果
Match not found Start of the region: 5