I have the following string:
http://www.powerwXXe.com/text1 123-456 text2 text3/
Can someone give me advice on how to get the value of text1, text2 and text3 and put them into a string. I have heard of regular expressions but have no idea how to use them.
Instead of going the RegEx route, if you know that the string will always be of a similar format, you can using string.Split, first on /, then on space and retrieve the results from the resulting string arrays.
string[] slashes = myString.Split('/');
string[] textVals = slashes[3].Split(' ');
// at this point:
// textVals[0] = "text1"
// textVals[1] = "123-456"
// textVals[2] = "text2"
// textVals[3] = "text3"
Here is a link on getting started with regular expressions in C#:Regular Expression Tutorial
I don't think it is appropriate to write out a tutorial here since the information is online, so please check out the link and let me know if you have a specific question.
Instead of using regex, you can use string.Fromat("http://myurl.com/{0}{1}{2}", value1, textbox2.Text, textbox3.Text) and format the url in whatever fashion. If you are looking to go the regex route, you can always check regexlib.
The use of regular expressions relies on patterns you see in your strings - you need to be able to generalize the pattern of strings you're looking for before you can use a regular expression.
For a problem of this scope, if you can pin down the pattern, you're probably better off using other string parsing methods, such as String.IndexOf and String.Split.
Regular expressions is a powerful tool, and certainly worth learning, but it might not be necessary here.
Based on the example you gave, it looks as though text1, text2 and text3 are separated by spaces? If so, and if you always know the positions they'll be in, you may want to skip regular expressions and just use .Split(' ') to split the string into an array of strings and then grab the pertinent items from there. Something like this:
string foo = "http://www.powerwXXe.com/text1 123-456 text2 text3/"
string[] fooParts = foo.Split(' ');
string text1 = fooParts[0].Replace("http://www.powerwXXe.com/", "");
string text2 = fooParts[2];
string text3 = fooParts[3].Replace("/", "");
You'd want to perform bounds checking on the string[] before trying to grab anything from it, but this would work. Regex is awesome for string parsing, but when it's simple stuff you need to do, sometimes it's overkill when simple methods from the string class will do.
It all depends on how much you know about about the string you are parsing. Where does the string come from and how much do you know about it's formating?
Based on your example string you could get away with something as simple as
string pattern = #"http://www.powerwXXe.com/(?<myGroup1>\S+)\s\S+\s(?<myGroup2>\S+)\s(?<myGroup3>\S+)/";
var reg = new System.Text.RegularExpressions.Regex(pattern);
string input = "http://www.powerwXXe.com/text1 123-456 text2 text3/";
System.Text.RegularExpressions.Match myMatch = reg.Match(input);
The caputerd strings would then be contained in myMatch.Groups["myGroup1"], ["myGroup2"], ["myGroup3"] respectivly.
This however assumes that your string always begins with http://www.powerwXXe.com/, that there will always be three groups to capture and that the groups are separated by a space (which is an illegal character in url's and would in almost all cases be converted to %20, which would have to be accounted for in the pattern).
So, how much do you know about your string? And, as some has already stated, do you really need regular expressions?
Related
I will have always an string like this:
"/FirstWord/ImportantWord/ThirdWord"
How can I extract the ImportantWord? Words can contain at most one space and they are separated by forward slashlike I put above, for example:
"/Folder/Second Folder/Content"
"/Main folder/Important/Other Content"
I always want to get the second word(Second Folder and Important considering above examples)
how about this:
string ImportantWord = path.Split('/')[2]; // Index 2 will give the required word
I hope you need not to use the String.Split option either with specific characters or with some regular expressions. Since the inputs are well qualified paths to a directory you can use Directory.GetParent method of the System.IO.Directory class, which will give you the parent Directory as DirectoryInfo. From that you can take the Name of Directory which will be the required text.
You can use like this :
string pathFirst = "/Folder/Second Folder/Content";
string pathSecond = "/Main folder/Important/Other Content";
string reqWord1 = Directory.GetParent(pathFirst ).Name; // will give you Second Folder
string reqWord2 = Directory.GetParent(pathSecond).Name; // will give you Important
Additional note: The method Directory.GetParent can be nested if you need to get a name in another level.
Also you may try this:
var stringValue = "/FirstWord/ImportantWord/ThirdWord";
var item = stringValue.Split('/').Skip(2).First(); //item: ImportantWord
There are several ways to solve this. The simplest one is using String.split
Char delimiter = '/';
String[] substrings = value.Split(delimiter);
String secondWord = substrings[1];
(you may want to do some input check to make sure the input is in the right format or else you will get some exception)
Other way is using regex when the pattern is simple /
If you are sure this is a path you can use other answer mention here
I want to find paths from a string and remove them, e.g.:
string1 = "'c:\a\b\c'!MyUDF(param1, param2,..) + 'c:\a\b\c'!MyUDF(param3, param4,..)..."`
I'd like a regex to find the pattern '[some path]'!MyUDF, and remove '[path]'.
Thanks.
Edit:
Example input:
string1 = "'c:\a\b\c'!MyUDF(param1, param2,..) + 'c:\a\b\c'!MyUDF(param3, param4,..)";
Expected output: "MyUDF(param1, param2,...) + MyUDF(param3, param4,...)"
where MyUDF is a function name, so it consists of only letters
input=Regex.Replace(input,"'[^']+'(?=!MyUDF)","");
In case if the path is followed by ! and some other word you can use
input=Regex.Replace(input,#"'[^']+'(?=!\w+)","");
Alright, if the ! is always in the string as you suggest, this Regex !(.*)?\( will get you what you want. Here is a Regex 101 to prove it.
To use it, you might do something like this:
var result = Regex.Replace(myString, #"!(.*)?\(");
The feature you want, if you are dealing with file paths, is in System.Path.
There are many methods there, but that is one of it's specific purposes.
i have a string that looks like this:
"/dir/location/test-load-ABCD.p"
and i need to parse out "ABCD" (where ABCD will be a different value every day)
The only things that i know that will always be consistent (to use for the logic for parsing) are:
There will always be be a ".p" after the value
There will always be a "test-load-" before the value.
The things i thought of was somehow grab everything past the last "/" and then remove the last 2 characters (to take case of the ".p" and then to do a
.Replace("test-load-", "")
but it felt kind of hacky so i wanted to see if people had any suggestions on a more elegant solution.
You can use a regex:
static readonly Regex parser = new Regex(#"/test-load-(.+)\.p");
string part = parser.Match(str).Groups[1].Value;
For added resilience, replace .+ with a character class containing only the characters that can appear in that part.
Bonus:
You probably next want
DateTime date = DateTime.ParseExact(part, "yyyy-MM-dd", CultureInfo.InvariantCulture);
Since this is a file name, use the file name parsing facility offered by the framework:
var fileName = System.IO.Path.GetFileNameWithoutExtension("/dir/location/test-load-ABCD.p");
string result = fileName.Replace("test-load-", "");
A “less hacky” solution than using Replace would be the use of regular expressions to capture the solution but I think this would be overkill in this case.
string input = "/dir/location/test-load-ABCD.p";
Regex.Match(input, #"test-load-([a-zA-Z]+)\.p$").Groups[1].Value
I am getting a string in the following format in the query string:
Arnstung%20Chew(20)
I want to convert it to just Arnstung Chew.
How do I do it?
Also how do I make sure that the user is not passing a script or anything harmful in the query string?
string str = "Arnstung Chew (20)";
string replacedString = str.Substring(0, str.IndexOf("(") -1 ).Trim();
string safeString = System.Web.HttpUtility.HtmlEncode(replacedString);
It's impossible to provide a comprehensive answer without knowing what variations might appear on your input text. For example, will there always be two words separated by a space followed by a number in parentheses? Or might there be other variations as well?
I have a lot of parsing code on my Black Belt Coder site, including a sscanf() replacement for .NET that may potentially be useful in your case.
This is my first stack message. Hope you can help.
I have several strings i need to break up for use later. Here are a couple of examples of what i mean....
fred-064528-NEEDED
frederic-84728957-NEEDED
sam-028-NEEDED
As you can see above the string lengths vary greatly so regex i believe is the only way to achieve what i want. what i need is the rest of the string after the second hyphen ('-').
i am very weak at regex so any help would be great.
Thanks in advance.
Just to offer an alternative without using regex:
foreach(string s in list)
{
int x = s.LastIndexOf('-')
string sub = s.SubString(x + 1)
}
Add validation to taste.
Something like this. It will take anything (except line breaks) after the second '-' including the '-' sign.
var exp = #"^\w*-\w*-(.*)$";
var match = Regex.Match("frederic-84728957-NEE-DED", exp);
if (match.Success)
{
var result = match.Groups[1]; //Result is NEE-DED
Console.WriteLine(result);
}
EDIT: I answered another question which relates to this. Except, it asked for a LINQ solution and my answer was the following which I find pretty clear.
Pimp my LINQ: a learning exercise based upon another post
var result = String.Join("-", inputData.Split('-').Skip(2));
or
var result = inputData.Split('-').Skip(2).FirstOrDefault(); //If the last part is NEE-DED then only NEE is returned.
As mentioned in the other SO thread it is not the fastest way of doing this.
If they are part of larger text:
(\w+-){2}(\w+)
If there are presented as whole lines, and you know you don't have other hyphens, you may also use:
[^-]*$
Another option, if you have each line as a string, is to use split (again, depending on whether or not you're expecting extra hyphens, you may omit the count parameter, or use LastIndexOf):
string[] tokens = line.Split("-".ToCharArray(), 3);
string s = tokens.Last();
This should work:
.*?-.*?-(.*)
This should do the trick:
([^\-]+)\-([^\-]+)\-(.*?)$
the regex pattern will be
(?<first>.*)?-(?<second>.*)?-(?<third>.*)?(\s|$)
then you can get the named group "second" to get the test after 2nd hyphen
alternatively
you can do a string.split('-') and get the 2 item from the array