在C＃中拆分字符串

Question

Let's say I have this string:

"param1,r:1234,p:myparameters=1,2,3" 

...and I would like to split it into:

param1
r:1234
p:myparameters=1,2,3

I've used the split function and of course it splits it at every comma. Is there a way to do this using regex or will I have to write my own split function?

Answer 1

Personally, I would try something like this:

,(?=[^,]+:.*?)

Basically, use a positive look-ahead to find a comma, followed by a "key-value" pair (this defined by a key, a colon, and more information [data] (including other commas). This should disqualify the commas between the numbers, too.

Answer 2

You can use ; for separating values which makes easy to work with it.

Since you have , for separation and also for values it is difficult to split it.

You have

string str = "param1,r:1234,p:myparameters=1,2,3"

Recommended to use

string str = "param1;r:1234;p:myparameters=1,2,3"

which can be splited as

var strArray = str.Split(';');

strArray[0];  // contains param1
strArray[1];  // r:1234
strArray[2];  // p:myparameters=1,2,3

Answer 3

I'm not sure how you would write a split that knew which commas to split on there, honestly.

Unless it's a fixed number each time in which case, just use the String.Split overload that takes an int specifying how many substrings to return at max

If you're going to have comma-delimited data that's not always a fixed number of items and it could have literal commas in the data itself, they really should be quoted. If you can control the input in any way, you should encourage that, and use an actual CSV parser instead of String.Split

Answer 4

That depends. You can't parse it with regex (or anything else) unless you can identify a consistent rule separating one group from another. Based on your sample, I can't clearly identify such a rule (though I have some guesses). How does the system know that p:myparameters=1,2,3 is a single item? For example, if there were another item after it, what would be the difference between that and the 1,2,3 ? Figure that out and you'll be pretty close to a solution.

If you're able to change the format of the input string, why not decide on a consistent delimiter between your groups? ; would be a good choice. Use an input like param1;r:1234;p:myparameters=1,2,3 and there will be no ambiguity where the groups are, plus you can just split on ; and you won't need regex.

Answer 5

The simplest approach would be changing your delimiter from "," to something like "|". Then you can split on "|" no problem. However if you can't change the delimiting character then maybe you could encode the sections in a fashion similar to CSV.

CSV files have the same issue... the standard there is to put double quotes "" around columns.

For example, your string would be "param1","r:1234","p:myparameters=1,2,3".

Then you could use the Microsoft.VisualBasic.FileIO.TextFieldParser to split/parse. You can include this in c# even though its in the VisualBasic namespace.

TextFieldParser

Answer 6

你的意思是：string [] str = System.Text.RegularExpression.Regex.Spilt（“param1，r：1234，p：myparameters = 1,2,3”，@“\\，”）;