Delete comments in a String?

Question

I want to remove simple // comments in a string. My String is called input

def input = '''test //kommentar
              |
              |//noch einer
              |
              |und      noch //einer'''.stripMargin()

The regex is \s*\/\/.*$ and can be tested here http://regexr.com?37ks0

In my code i have input = input.replaceAll(/\s*\/\/.*$/ , '')

But it doesn't work. Can anybody help me ?

Answer 1

At the very least, you need to make sure that the $ anchor is allowed to match the end of each line, not just the end of the entire string:

input = input.replaceAll(/(?m)\s*\/\/.*$/ , '')

But what if // occur, say, in a quoted string? Or in any other circumstance where they do not mean "start of comment"?

Answer 2

Ok i got the answer from a college.

If it was one line, the code in the description works. Because I have multilines, I have to use the following:

input = input.replaceAll(Pattern.compile(/\s*\/\/.*$/, Pattern.MULTILINE), '')

Answer 3

And if you want to keep the //noch einer line as a blank line in your output, you could try:

input.replaceAll( '(?m)//.*$' , '' )

Of course if the line above was in your input text, then all of this regex munging would break the input code, as that line would become input.replaceAll('(?m)

As a general rule, this sort of regular expression parsing of code is never a good idea