vb.net 使用正则表达式拆分字符串

Question

I have requrement to split a string with regex on several rules and I do something with help of previous posts here but I don't know how to do it completelly.

Input string (intentionally written ugly) is:

Berlin "New York"Madrid 'Frankfurt Am Main' Quebec Łódź   München Seattle,Milano

Splitting code is:

Dim subStrings() As String = Regex.Split(myText, """([^""]*)""|,| ")

Result of this is:

0)  
1)  
2)Berlin  
3)  
4)New York  
5)Madrid  
6)'Frankfurt  
7)Am  
8)Main'  
9)Quebec  
10)Łódź  
11)  
12)  
13)München  
14)Seattle  
15)Milano  

In short, string should be splitted into array by " " (space) and/or "," char and/or by single or double quote. Quoted terms should be treated as a single word. This means that term in single quotes (at place 6) will be treated a same like a term in double quotes. That way 'Frankfurt Am Main' at place 6. will be "one word" same as is "New York" at place 4. Also, I would like if regex can be made that empty matches would not go to subStrings() array. After all an ideal result from given example should be:

0)Berlin  
1)New York  
2)Madrid  
3)Frankfurt Am Main  
4)Quebec  
5)Łódź  
6)München  
7)Seattle  
8)Milano  

So, please if someone know how to solve this concrete regex for me.

Answer 1

You may extract the strings by using Regex.Matches with the following regex:

"([^"]*)"|'([^']*)'|([^,\s]+)

See the regex demo .

Details

• "([^"]*)" - " , then Group 1 matching any 0+ chars other than " , and then "
• | - or
• '([^']*)' - ' , then Group 2 matching any 0+ chars other than ' , and then '
• | - or
• ([^,\\s]+) - Group 3: any 1+ chars other than , and whitespace

VB.NET code snippet:

Dim text = "Berlin ""New York""Madrid 'Frankfurt Am Main' Quebec Łódź   München Seattle,Milano"
Dim pattern As String = """([^""]*)""|'([^']*)'|([^,\s]+)"
Dim matches() As String = Regex.Matches(text, pattern) _
          .Cast(Of Match)() _
          .Select(Function(m) m.Groups(1).Value & m.Groups(2).Value & m.Groups(3).Value) _
          .ToArray()

Results:

The same can be obtained with the following Regex.Split approach:

pattern = """([^""]*)""|'([^']*)'|[,\s]+"
Dim matches() As String = Regex.Split(text, pattern).Where(Function(m) Not String.IsNullOrWhiteSpace(m)).ToArray()

See the regex demo .