如何在 Java 中将分隔符与 Scanner.useDelimiter 一起使用? [英] How do I use a delimiter with Scanner.useDelimiter in Java?
本文介绍了如何在 Java 中将分隔符与 Scanner.useDelimiter 一起使用?的处理方法,对大家解决问题具有一定的参考价值,需要的朋友们下面随着小编来一起学习吧!
问题描述
sc = new Scanner(new File(dataFile));
sc.useDelimiter(",|
");
我不明白分隔符是如何工作的,有人可以通俗地解释一下吗?
I don't understand how delimiter works, can someone explain this in layman terms?
推荐答案
扫描器还可以使用除空格以外的分隔符.
The scanner can also use delimiters other than whitespace.
Easy example from Scanner API:
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();
重点是理解正则表达式(regex
)Scanner::useDelimiter
.查找 useDelimiter
教程 这里.
The point is to understand the regular expressions (regex
) inside the Scanner::useDelimiter
. Find an useDelimiter
tutorial here.
从正则表达式开始在这里您可以找到一个不错的教程.
To start with regular expressions here you can find a nice tutorial.
abc… Letters
123… Digits
d Any Digit
D 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 9
w Any Alphanumeric character
W Any Non-alphanumeric character
{m} m Repetitions
{m,n} m to n Repetitions
* Zero or more repetitions
+ One or more repetitions
? Optional character
s Any Whitespace
S Any Non-whitespace character
^…$ Starts and ends
(…) Capture Group
(a(bc)) Capture Sub-group
(.*) Capture all
(ab|cd) Matches ab or cd
这篇关于如何在 Java 中将分隔符与 Scanner.useDelimiter 一起使用?的文章就介绍到这了,希望我们推荐的答案对大家有所帮助,也希望大家多多支持IT屋!
查看全文