正则表达式“ [[X？+]””元字符Java
可能量词[X？+]匹配一次存在的X或根本不存在的X。
示例
package com.tutorialspoint;
import java.util.regex.Matcher;
import java.util.regex.Pattern;
public class PossesiveQuantifierDemo {
private static final String REGEX = "T?+";
private static final String INPUT = "abcdTatW";
public static void main(String[] args) {
// create a pattern
Pattern pattern = Pattern.compile(REGEX);
// get a matcher object
Matcher matcher = pattern.matcher(INPUT);
while(matcher.find()) {
//Prints the start index of the match.
System.out.println("Match String start(): "+matcher.start());
}
}
}输出结果
Match String start(): 0 Match String start(): 1 Match String start(): 2 Match String start(): 3 Match String start(): 4 Match String start(): 5 Match String start(): 6 Match String start(): 7 Match String start(): 8