在scala中，如何在字符串中查找所有出现的\\ $ [0-9] +并替换它们

Question

以下简单代码失败（我希望结果为"abc$1%s"）：

  "\\$[0-9]+".r
    .replaceAllIn(
      "abc$1", {
        mtch =>
          mtch.toString() + "%s"
      })

用

No group 1
java.lang.IndexOutOfBoundsException: No group 1

我已正确转义美元符号并避免所有前瞻/回顾控制字符，为什么它仍然失败？

Answer 1

The group error means you don't have a parenthesis delimited group defined.

Something like "(\\$[0-9]+)" would define your whole regex as a group.