如何在Java Scanner中使用定界符？

扫描仪还可以使用空格以外的定界符。

来自Scanner API的简单示例：

 String input = "1 fish 2 fish red fish blue fish"; // \s* means 0 or more repetitions of any whitespace character  // fish is the pattern to find Scanner s = new Scanner(input).useDelimiter("\s*fish\s*"); System.out.println(s.nextInt());   // prints: 1 System.out.println(s.nextInt());   // prints: 2 System.out.println(s.next());      // prints: red System.out.println(s.next());      // prints: blue // don't forget to close the scanner!! s.close(); 

关键是要了解内的正则表达式

（regex）Scanner::useDelimiter

useDelimiter

要从正则表达式开始，你可以在这里找到一个不错的教程。

笔记

abc…    Letters123…    Digitsd      Any DigitD      Any Non-digit character.       Any Character.      Period[abc]   only a, b, or c[^abc]  Not a, b, nor c[a-z]   Characters a to z[0-9]   Numbers 0 to 9w      Any Alphanumeric characterW      Any Non-alphanumeric character{m}     m Repetitions{m,n}   m to n Repetitions*       Zero or more repetitions+       One or more repetitions?       Optional characters      Any WhitespaceS      Any Non-whitespace character^…$     Starts and ends(…)     Capture Group(a(bc)) Capture Sub-group(.*)    Capture all(ab|cd) Matches ab or cd