regex101: Match double quoted or single quoted multi line string in code.

Pro

Group 1("|')

1st Alternative"

"the literal " (34₁₀ / 42₈ / 22₁₆)

2nd Alternative'

'the literal ' (39₁₀ / 47₈ / 27₁₆)

Group 2((?!(?!\\)(\1|\n))|(\\(.|\n))|((?!\\).))*?

*?repeats the group contents below any number of times:

1st Alternative(?!(?!\\)(\1|\n))

Negative Lookahead(?!(?!\\)(\1|\n))

Negative Lookahead(?!\\)

\\the literal \ (92₁₀ / 134₈ / 5C₁₆)

Group 3(\1|\n)

1st Alternative\1

\1the text saved by group 1

2nd Alternative\n

\na line-feed (newline) character (ASCII 10)

2nd Alternative(\\(.|\n))

Group 4(\\(.|\n))

\\the literal \ (92₁₀ / 134₈ / 5C₁₆)

Group 5(.|\n)

1st Alternative.

.any Unicode character (except for line terminators)

2nd Alternative\n

\na line-feed (newline) character (ASCII 10)

3rd Alternative((?!\\).)

Group 6((?!\\).)

Negative Lookahead(?!\\)

\\the literal \ (92₁₀ / 134₈ / 5C₁₆)

.any Unicode character (except for line terminators)

Group 7(\1)

\1the text saved by group 1

Global pattern flags

g modifier: global. Finds all matches instead of stopping after the first

25 tokens

Regular Expression

("|')((?!(?!\\)(\1|\n))|(\\(.|\n))|((?!\\).))*?(\1)

New

"valid line"

'valid line 2'

''

""

"'''"
"''''"
'"""'
'""""'

"hello new line\
hello another line\
end blank line"

'hello blank line\
\ \\g\
end blank line'

"\'"

"\""

"errors"

"broken line
"

'broken line 
'

"broken line 2 \ffd
\hellod
"
'\'
"\"
"""

'''

Substitution

newstr

"valid line"

'valid line 2'

''

""

"'''"
"''''"
'"""'
'""""'

"hello new line\
hello another line\
end blank line"

'hello blank line\
\ \\g\
end blank line'

"\'"

"\""

"errors"

"broken line
"

'broken line 
'

"broken line 2 \ffd
\hellod
"
'\'
"\"
"""

'''