Regex: How do I replace part of a pattern and reference a variable within it?

Question

I want to match a pattern, replace part of the pattern, and use a variable within the pattern as part of the replacement string.

Is this correct?

/s/^((\\s

Answer 1

This is called a backreference, and you use \i to refer to the i'th captured group from the pattern.

So for the pattern ^((\s+)private\sfunction\s__construct\(\)), the replacement is \2def __init__.