C# Regex 选择带括号的预定义关键字

Question

I have a text which is

SMA(20, V1) > 200000 AND C1 < LowerBollingerBand(20, 2)

after applying regex I need a result like this

SMA(20, V1) LowerBollingerBand(20, 2)

I can select SMA and LowerBollingerBand by defining these keywords explicitly like this

(SMA|LowerBollingerBand)(\()

But I am unable to select whatever comes between brackets followed by brackets

Answer 1

In case your strings cannot have nested balanced parentheses, you may use a [^()] negated character class to match any symbol but ( and ) after \\( and add a \\) after to match the close parentheses:

(SMA|LowerBollingerBand)\([^()]*\)

See the regex demo

Details :

• (SMA|LowerBollingerBand) - either SMA or LowerBollingerBand
• \\( - a (
• [^()]* - 0+ chars other than ( and )
• \\) - a ) .

In case there are balanced nested parentheses, use

(SMA|LowerBollingerBand)\((?>[^()]+|(?<c>)\(|(?<-c>)\))*(?(c)(?!))\)

See this regex demo

The \\((?>[^()]+|(?<c>)\\(|(?<-c>)\\))*(?(c)(?!))\\) construct matches balanced nested parentheses, see this answer for a description . More on this can be found at the regular-expressions.info Balancing Groups .