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- Why does String.split need pipe delimiter to be escaped? 3 answers
- 为什么String.split需要管道分隔符进行转义? 3个答案
I tried to read about regex and escaping, but no luck.
我试着阅读关于正则表达式和逃避,但没有运气。
I have a string that looks like this:
我有一个看起来像这样的字符串:
String s = "4/18/2015|Planned|Linux|Maintenance";
And I want to split it with the delimiter '|' :
我想用分隔符'|'拆分它:
String[] tokens = s.split("|");
The correct results I am expecting which are
我期待的正确结果是什么
tokens[0] is "4/18/2015",
tokens[1] is "Planned",
tokens[2] is "Linux",
token[3] is "Maintenance",
yet it's giving me some weird result like this:
然而它给了我一些奇怪的结果:
tokens[0] is null
tokens[1] is 4
tokens[2] is /
and tokens[3] is 1
I am guessing it's because of the slashes '/' in the date that's why. I tried to search for many existing questions and tried the suggested methods as well but to no avail.
我猜这是因为日期中的斜线'/'就是为什么。我试图搜索许多现有的问题,并尝试了建议的方法,但无济于事。
3 个解决方案
#1
3
Just use
只是用
split("\\x7C")
or
要么
split("\\|")
You need to escape or use corresponding unicode value when splitting against the pipeline char '|'.
在拆分管道char'|'时,您需要转义或使用相应的unicode值。
#2
4
@ mushfek0001做对了。
The pipe in most regex dialects is a metacharacter for the alternation; basically what you ask the regex engine to do here is: "split against the empty string or... the empty string".
大多数正则表达方言中的管道是交替的元字符;基本上你要求正则表达式引擎在这里做的是:“分裂空字符串或...空字符串”。
And, uh, it means you would potentially get empty each time, except that the regex engine is not a fool, and if an empty match is detected in a split the engine will advance one character before splitting again... Hence your result (not sure why the first element is null
and not the empty string, though).
并且,呃,这意味着你每次都可能变空,除了正则表达式引擎不是傻瓜,如果在分割中检测到空匹配,引擎将在再次分裂之前前进一个字符...因此你的结果(不知道为什么第一个元素为null而不是空字符串。
Therefore, you should split against "\\|"
, not "|"
.
因此,您应该拆分“\\ |”,而不是“|”。
What is more, if you do this repeatedly, use a Pattern
instead:
更重要的是,如果你反复这样做,请改用Pattern:
private static final Pattern PIPE = Pattern.compile("\\|");
// ...
final String[] tokens = PIPE.split(yourInput);
#3
2
escape the pipe character:
逃避管道角色:
s.split("\\|");
because pipe sign in regex means OR, so to escape it you need \|
but in regex you need to escape \
too so \\|
will work.
因为管道登录正则表达式是OR,所以为了逃避它你需要\ |但是在正则表达式中,你需要逃避\ \所以\\ |将工作。
or as mushfek0001 suggested:
或作为mushfek0001建议:
split("\\x7C")
#1
3
Just use
只是用
split("\\x7C")
or
要么
split("\\|")
You need to escape or use corresponding unicode value when splitting against the pipeline char '|'.
在拆分管道char'|'时,您需要转义或使用相应的unicode值。
#2
4
@ mushfek0001做对了。
The pipe in most regex dialects is a metacharacter for the alternation; basically what you ask the regex engine to do here is: "split against the empty string or... the empty string".
大多数正则表达方言中的管道是交替的元字符;基本上你要求正则表达式引擎在这里做的是:“分裂空字符串或...空字符串”。
And, uh, it means you would potentially get empty each time, except that the regex engine is not a fool, and if an empty match is detected in a split the engine will advance one character before splitting again... Hence your result (not sure why the first element is null
and not the empty string, though).
并且,呃,这意味着你每次都可能变空,除了正则表达式引擎不是傻瓜,如果在分割中检测到空匹配,引擎将在再次分裂之前前进一个字符...因此你的结果(不知道为什么第一个元素为null而不是空字符串。
Therefore, you should split against "\\|"
, not "|"
.
因此,您应该拆分“\\ |”,而不是“|”。
What is more, if you do this repeatedly, use a Pattern
instead:
更重要的是,如果你反复这样做,请改用Pattern:
private static final Pattern PIPE = Pattern.compile("\\|");
// ...
final String[] tokens = PIPE.split(yourInput);
#3
2
escape the pipe character:
逃避管道角色:
s.split("\\|");
because pipe sign in regex means OR, so to escape it you need \|
but in regex you need to escape \
too so \\|
will work.
因为管道登录正则表达式是OR,所以为了逃避它你需要\ |但是在正则表达式中,你需要逃避\ \所以\\ |将工作。
or as mushfek0001 suggested:
或作为mushfek0001建议:
split("\\x7C")