How Can a Regex Efficiently Remove C-Style Multiline Comments from a String?

Matching C-Style Multiline Comments with Regex

In need of extracting strings free of C-style multiline comments? Let's delve into a regex solution that effectively tackles this task.

To efficiently remove multiline comments like / this is comment */ from a given string, we turn to a specific regex:

/\*[^*]*\*+(?:[^/*][^*]*\*+)*\*/

This complex pattern decomposes as follows:

• /* - Initiates the comment with a forward slash followed by an asterisk.
• ¹* - Matches any character except for 0 or more times, followed by one or more literal asterisks.

• (?:²¹* ) - Zero or more repetitions of the following:

  • ²¹* - A sequence of non-/) and non- characters followed by one or more asterisks.
• / - Terminates the comment with a closing forward slash.

This regex comprehensively identifies multiline comments by matching these segments one by one. In contrast to David's regex, which requires 26 steps to process the example string, this optimized pattern completes the task in a mere 12 steps. For extensive input strings, the efficiency advantage becomes apparent, as David's solution may face stack overflow issues due to its intricate structure.

By utilizing this highly efficient regex, you can effortlessly remove multiline comments from your input strings, leaving them pristine and devoid of unnecessary clutter.

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1. * ↩
2. /* ↩

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