个回答

• 慕粉3936973

  2016-10-31 10:30:06

  已采纳

  public static void main(String[] args) { 
          String matcherStr = "This is the first Java";
          matcherStr += "\nAnd";
          matcherStr += "\nThis is the second Python";
          Matcher matcher = Pattern.compile("Java$", Pattern.MULTILINE).matcher(matcherStr);
          
          int i=0;
          while(matcher.find()){
             i++;
          }
          System.out.println(i);
  }

  There is one match (i=1) for Java in the first line. This is mutiline, so the whole matcherStr is something like:

  This is the first Java

  And
  

  This is the second Python

  
  

  public static void main(String[] args) { 
          String matcherStr = "This is the first Java";
          matcherStr += "\nAnd";
          matcherStr += "\nThis is the second Java";
          Matcher matcher = Pattern.compile("Java$", Pattern.MULTILINE).matcher(matcherStr);
          
          int i=0;
          while(matcher.find()){
             i++;
          }
          System.out.println(i);
  }

  There are two matchs (i=2) for Java in the first line. This is mutiline, so the whole matcherStr is something like:

  This is the first Java

  And
  

  This is the second Java

  
  

  public static void main(String[] args) { 
          String matcherStr = "This is the first Java";
          matcherStr += "\nAnd";
          matcherStr += "\nThis is the second Python";
          Matcher matcher = Pattern.compile("Java$").matcher(matcherStr);
          
          int i=0;
          while(matcher.find()){
             i++;
          }
          System.out.println(i);
  }

  There is no match (i=0) for Java. This is not mutiline, so the whole matcherStr is something like:

  This is the first Java\nAnd\nThis is the second Python

  
  

  public static void main(String[] args) { 
          String matcherStr = "This is the first Java";
          matcherStr += "\nAnd";
          matcherStr += "\nThis is the second Java";
          Matcher matcher = Pattern.compile("Java\\Z", Pattern.MULTILINE).matcher(matcherStr);
          
          int i=0;
          while(matcher.find()){
             i++;
          }
          System.out.println(i);
  }

  There is one match (i=1) for Java with multiline.  The same as without multiline.
  

  In this case: If Pattern.compile("Java$", Pattern.MULTILINE), there are two matches.
  

  
  

  public static void main(String[] args) { 
          String matcherStr = "This is the first Java";
          matcherStr += "\nAnd";
          matcherStr += "\nThis is the second Java";
          Matcher matcher = Pattern.compile("Java\\Z").matcher(matcherStr);
          
          int i=0;
          while(matcher.find()){
             i++;
          }
          System.out.println(i);
  }

  There is one match (i=1) for Java without multiline.
  

  
  
  0

• 慕粉3936973

  2016-10-24 15:26:21

  ^ 
  指定匹配必须出现在字符串的开头或行的开头。
  

  \A 
  指定匹配必须出现在字符串的开头（忽略 Multiline 选项）。
  

  
  $ 
  指定匹配必须出现在以下位置：字符串结尾、字符串结尾的 \n 之前或行的结尾。
  
  \Z 
  指定匹配必须出现在字符串的结尾或字符串结尾的 \n 之前（忽略 Multiline 选项）。 
  
  

  
  

  
  

  1