为什么 String.replaceAll() 在 Java 8 和 Java 9 中的工作方式不同？
Why does String.replaceAll() work differently in Java 8 from Java 9?
为什么这段代码在java-8 but o2 in java-9或以上输出02？
"o2".replaceAll("([oO])([^[0-9-]])", "0")
很可能是由于 JDK-6609854 and JDK-8189343 报告了负面嵌套字符 类 处理（在您的示例中 [^[0-9-]]）。此行为已在 9 和 10 中修复，但修复未反向移植到 8。Java 8 的错误解释为：
In Java, the negation does not apply to anything appearing in
nested [brackets]
So [^c] does not match "c", as you would expect.
[^[c]] does match "c". Not what I would expect.
[[^c]] does not match "c"
The same holds true for ranges or property expressions - if they're
inside brackets, a negation at an out level does not affect them.
[^a-z] is opposite from [^[a-z]]
为什么这段代码在java-8 but o2 in java-9或以上输出02？
"o2".replaceAll("([oO])([^[0-9-]])", "0")
很可能是由于 JDK-6609854 and JDK-8189343 报告了负面嵌套字符 类 处理（在您的示例中 [^[0-9-]]）。此行为已在 9 和 10 中修复，但修复未反向移植到 8。Java 8 的错误解释为：
In Java, the negation does not apply to anything appearing in nested
[brackets]So
[^c]does not match "c", as you would expect.
[^[c]]does match "c". Not what I would expect.
[[^c]]does not match "c"The same holds true for ranges or property expressions - if they're inside brackets, a negation at an out level does not affect them.
[^a-z]is opposite from[^[a-z]]