Regular Expressions 101

Pro

Negative Lookbehind(?<!$(?=[^()\n]*$)[^()\n]*)

\(the literal ( (40₁₀ / 50₈ / 28₁₆)

Positive Lookahead(?=[^()\n]*\))

Negated Character Class[^()\n]*

*matches any number of characters outside the set below:

(the literal ( (40₁₀ / 50₈ / 28₁₆)

)the literal ) (41₁₀ / 51₈ / 29₁₆)

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

\)the literal ) (41₁₀ / 51₈ / 29₁₆)

Negated Character Class[^()\n]*

*matches any number of characters outside the set below:

(the literal ( (40₁₀ / 50₈ / 28₁₆)

)the literal ) (41₁₀ / 51₈ / 29₁₆)

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

bigthe literal text big (case sensitive)

Global pattern flags

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

m modifier: multiline. Causes ^ and $ to match the start and end of each line, not only the start and end of the string

Detailed match information will be displayed here automatically.

25 tokens

Regular Expression

(?<!\((?=[^()\n]*\))[^()\n]*)big

New

Should Match: 
I like big cakes
I like (big cakes
I like big) cakes
I like xx big xx cakes
I like ( xx big xx cakes
I like xx big xx) cakes

Should not Match: 
I like (big) cakes
I like (xx big xx) cakes

Substitution

Should Match: 
I like big cakes
I like (big cakes
I like big) cakes
I like xx big xx cakes
I like ( xx big xx cakes
I like xx big xx) cakes

Should not Match: 
I like (big) cakes
I like (xx big xx) cakes