英文:
Regex replacing everything before a predefined range of chars - Java
问题
我有一些字符串值，我想删除或替换掉"TV|TH"之前的所有内容。我的问题是，尽管使用了正确的语法，字符串似乎保持不变。
String test = "10TH";
String replaceBeforeSide = test.replaceAll("^(TH|TV)+", "");
System.out.println(replaceBeforeSide);
//期望结果 = "TH";
英文:
I have string values where I want to remove or replace everything that comes before "TV|TH". My problem is that despite using the correct syntax, the string seems to stay the same.
String test = "10TH";
String replaceBeforeSide = test.replaceAll("^\\(TH|TV)+", "");
System.out.println(replaceBeforeSide);
//Desired result = "TH";
答案1
得分: 2
Sure, here is the translated code portion:
将我的评论转换为答案，以便将来的访问者可以轻松找到解决方案。
您可以使用一个简单的正则表达式与一个捕获组：
replaceBeforeSide = test.replaceAll(".+?(TH|TV)", "$1");
或者更简短的：
replaceBeforeSide = test.replaceAll(".+?(T[HV])", "$1");
使用`.+?`，我们匹配1个或多个任何字符（非贪婪），然后匹配并捕获在第1组中的`(TH|TV)`。在替换中，我们只需放置`$1`，以便仅删除`(TH|TV)`之前的字符串。
我们还可以使用前瞻而避免捕获组：
replaceBeforeSide = test.replaceAll(".+?(?=T[HV])", "");
如果要忽略大小写，请使用内联修饰符`(?i)`：
replaceBeforeSide = test.replaceAll("(?i).+?(?=T[HV])", "");
英文:
Converting my comment to answer so that solution is easy to find for future visitors.
You could use a simple regex with a capture group:
replaceBeforeSide = test.replaceAll(".+?(TH|TV)", "$1");
or even shorter:
replaceBeforeSide = test.replaceAll(".+?(T[HV])", "$1");
Using .+?, we are matching 1+ of any character (non-greedy) before matching (TH|TV) that we capture in group #1.
In replacement we just put $1 back so that only string before (TH|TV) is removed.
We could also use a lookahead and avoid capture group:
replaceBeforeSide = test.replaceAll(".+?(?=T[HV])", "");
If you want to match ignore case then use inline modifier (?i):
replaceBeforeSide = test.replaceAll("(?i).+?(?=T[HV])", "");
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