java 如何使用正则表达式根据模式拆分字符串
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How to split a string based on a pattern using regex
提问by prasanth
I have trouble splitting string based on regex.
我无法根据正则表达式拆分字符串。
String str = "1=(1-2,3-4),2=2,3=3,4=4";
Pattern commaPattern = Pattern.compile("\([0-9-]+,[0-9-]+\)|(,)") ;
String[] arr = commaPattern.split(str);
for (String s : arr)
{
System.out.println(s);
}
Expected output,
预期输出，
1=(1-2,3-4)
2=2
3=3
4=4
Actual output,
实际输出，
1=
2=2
3=3
4=4
回答by Anirudha
This regex would splitas required
此正则表达式将根据需要 拆分
,(?![^()]*\))
------------
|->split with , only if it is not within ()
回答by Bart Kiers
This isn't well suited for a split(...). Consider scanning through the input and matching instead:
这不太适合split(...). 考虑扫描输入和matching：
String str = "1=(1-2,3-4),2=2,3=3,4=4";
Matcher m = Pattern.compile("(\d+)=(\d+|\([^)]*\))").matcher(str);
while(m.find()) {
String key = m.group(1);
String value = m.group(2);
System.out.printf("key=%s, value=%s\n", key, value);
}
which would print:
这将打印：
key=1, value=(1-2,3-4)
key=2, value=2
key=3, value=3
key=4, value=4
回答by Hurda
You will have to use some look ahead mechanism here. As I see it you are trying to split it on comma that is not in parenthesis. But your regular expressions says:
您将不得不在这里使用一些前瞻机制。正如我所看到的，您正试图将它拆分为不在括号中的逗号。但是你的正则表达式说：
Split on comma OR on comma between numbers in parenthesis
So your String gets splitted in 4 places 1) (1-2,3-4) 2-4) comma
所以你的字符串被分成 4 个位置 1) (1-2,3-4) 2-4) 逗号
回答by Achintya Jha
String[] arr = commaPattern.split(str);
should be
应该
String[] arr = str.split(commaPattern);
