java - 正则表达式: ignore what is quoted in a string

Question

如果我有字符串 "This is > than" something 1=3 and "else = true" (不要试图理解它的含义，它只是一个示例:P)我如何替换引号中未包含的自定义模式？例如，将第一个运算符“=”(等于)替换为“<”，结果为字符串 "This is > than" something 1<3 and "else = true" 。预先感谢您。

Answer 1

您可以尝试以下正则表达式来替换所有 =它存在于 " 之外与 <符号。

=(?=(?:[^"]*"[^"]*")*[^"]*$)

替换字符串:

<

DEMO

System.out.println("\"This is > than\" something 1=3 and \"else = true\"".replaceAll("=(?=(?:[^\"]*\"[^\"]*\")*[^\"]*$)", "<"));

输出:

"This is > than" something 1<3 and "else = true"