Java StringTokenizer，空null标记 [英] Java StringTokenizer, empty null tokens

问题描述

我正在尝试将一个字符串拆分为29个令牌..... stringtokenizer不会返回null令牌。我试过string.split，但我相信我做错了什么：

I am trying to split a string into 29 tokens..... stringtokenizer won't return null tokens. I tried string.split, but I believe I am doing something wrong:

String [] strings = line.split(",", 29);

样本输入：

10150,15:58,23:58,16:00,00:00,15:55,23:55,15:58,00:01,16:03,23:58,,,,,16:00,23:22,15:54,00:03,15:59,23:56,16:05,23:59,15:55,00:01,,,,
10155,,,,,,,,,,,07:30,13:27,07:25,13:45,,,,,,,,,,,07:13,14:37,08:01,15:23
10160,10:00,16:02,09:55,16:03,10:06,15:58,09:48,16:07,09:55,16:00,,,,,09:49,15:38,10:02,16:04,10:00,16:00,09:58,16:01,09:57,15:58,,,,

推荐答案

如果你想保留尾随的空字符串，但是你没有想要给出最大的幻数，使用负限制：

If you want the trailing empty strings to be kept, but you don't want to give a magic number for maximum, use a negative limit:

line.split(",", -1)

如果 line.equals（a，c），然后 line.split（，， - 1）[1] .isEmpty（）;它不是 null 。这是因为当，是分隔符时，,,在两个分隔符之间有一个空字符串，而不是 null 。

---

示例：

使用上面的解释，请考虑以下示例： ,,

If line.equals("a,,c"), then line.split(",", -1)[1].isEmpty(); it's not null. This is because when "," is the delimiter, then ",," has an empty string between the two delimiters, not null.

---

Example:

Using the explanation above, consider the following example: ",,"

虽然您可能期望，， null ，，。

实际结果是，，和，

---

如果你想要 null 而不是<$返回的数组中的空字符串c $ c> split ，然后你必须手动扫描数组并用 null 替换它们。我不知道为什么 s == null 优于 s.isEmpty（）。

---

If you want null instead of empty strings in the array returned by split, then you'd have to manually scan the array and replace them with null. I'm not sure why s == null is better than s.isEmpty(), though.

• Java String.indexOf 和空字符串

• Java String.indexOf and empty strings

这篇关于Java StringTokenizer，空null标记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！