預定義字元類別 . 匹配

說明

字元類別 . 可匹配任意字元。

範例

以下示例展示了預定義字元類別匹配的用法。

package com.tutorialspoint;

import java.util.regex.Matcher;
import java.util.regex.Pattern;

public class PredefinedCharacterClassDemo {
   private static final String REGEX = ".";
   private static final String INPUT = "dbcabcab12\tc";

   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());
      }
   }
}

讓我們編譯並執行上述程式，這將生成以下結果 −

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
Match String start(): 9
Match String start(): 10
Match String start(): 11