RegEx - 获取未包装的元素数

Question

For example I have a string like this:

first:second:third"test:test":fourth

I want to count the ':' and later to split every ':' to get the strings.

This is my regex:

/(.*):(.*)/iU

I don't know if this is the best solution, but it works. There is a different between a '.' and a "[...] : [...]" so I need to seperate them. I realized that my regex counts the : but continues when the : is between ".

I tried to solve this with this regex:

/(((.*)[^"]):((.*)[^"]))/iU

I thought this is the right way, but it isn't. I tried to learn the regex syntax, but I don't understand this problem.

This regex just means: search for ':' - every think can be infornt and after it EXCEPT wehen a " is in front of it AND a " is after it.

Maybe you can help me.

edit: I use my regex in PHP - maybe this is an important information

Answer 1

How about using

$result = preg_split(
    '/:       # Match a colon
    (?=       # only if followed by
     (?:      # the following group:
      [^"]*"  #  Any number of characters except ", followed by one "
      [^"]*"  #  twice in a row (to ensure even number of "s)
     )*       # (repeated zero or more times)
     [^"]*    # followed by any number of non-quotes until...
     $        # the end of the string.
    )         # End of lookahead assertion
    /x', 
    $subject);

which will give you the result

first
second
third"test:test"
fourth

directly?

This regex splits on a : only if it's followed by an even number of quotes. This means that it won't split on a : inside a string: