I have the following string:
This isMyTest testing
I want to get isMyTest as a result. I only have two first characters available("is"). The rest of the word can vary.
Basically, I need to select a first word delimeted by spaces which starts with chk.
I've started with the following:
if (text.contains(" is"))
{
text.LastIndexOf(" is"); //Should give me index.
}
now I cannot find the right bound of the word since I need to match on something like
You can use regular expressions:
string pattern = #"\bis";
string input = "This isMyTest testing";
return Regex.Matches(input, pattern);
You can use IndexOf to get the index of the next space:
int startPosition = text.LastIndexOf(" is");
if (startPosition != -1)
{
int endPosition = text.IndexOf(' ', startPosition + 1); // Find next space
if (endPosition == -1)
endPosition = text.Length - 1; // Select end if this is the last word?
}
What about using a regex match? Generally if you are searching for a pattern in a string (ie starting with a space followed by some other character) regex are perfectly suited to this. Regex statements really only fall apart in contextually sensitive areas (such as HTML) but are perfect for a regular string search.
// First we see the input string.
string input = "/content/alternate-1.aspx";
// Here we call Regex.Match.
Match match = Regex.Match(input, #"[ ]is[A-z0-9]*", RegexOptions.IgnoreCase);
// Here we check the Match instance.
if (match.Success)
{
// Finally, we get the Group value and display it.
string key = match.Groups[1].Value;
Console.WriteLine(key);
}
Related
I have this string (it's from EDI data):
ISA*ESA?ISA*ESA?
The * indicates it could be any character and can be of any length.
? indicates any single character.
Only the ISA and ESA are guaranteed not to change.
I need this split into two strings which could look like this: "ISA~this is date~ESA|" and
"ISA~this is more data~ESA|"
How do I do this in c#?
I can't use string.split, because it doesn't really have a delimeter.
You can use Regex.Split for accomplishing this
string splitStr = "|", inputStr = "ISA~this is date~ESA|ISA~this is more data~ESA|";
var regex = new Regex($#"(?<=ESA){Regex.Escape(splitStr)}(?=ISA)", RegexOptions.Compiled);
var items = regex.Split(inputStr);
foreach (var item in items) {
Console.WriteLine(item);
}
Output:
ISA~this is date~ESA
ISA~this is more data~ESA|
Note that if your string between the ISA and ESA have the same pattern that we are looking for, then you will have to find some smart way around it.
To explain the Regex a bit:
(?<=ESA) Look-behind assertion. This portion is not captured but still matched
(?=ISA) Look-ahead assertion. This portion is not captured but still matched
Using these look-around assertions you can find the correct | character for splitting
Simply use the
int x = whateverString.indexOf("?ISA"); // replace ? with the actual character here
and then just use the substring from 0 to that indexOf, indexOf to length.
Edit:
If ? is not known,
can we just use the regex Pattern and Matcher.
Matcher matcher = Patter.compile("ISA.*ESA").match(whateverString);
if(matcher.find()) {
matcher.find();
int x = matcher.start();
}
Here x would give that start index of that match.
Edit: I mistakenly saw it as java one, for C#
string pattern = #"ISA.*ESA";
Regex myRegex = new Regex(pattern, RegexOptions.IgnoreCase);
Match m = myRegex.Match(whateverString); // m is the first match
while (m.Success)
{
Console.writeLine(m.value);
m = m.NextMatch(); // more matches
}
RegEx will probably be the best for this. See this link
Mask would be
ISA(?<data1>.*?)ESA.ISA(?<data2>.*?)ESA.
This will give you 2 groups with data you need
Match match = Regex.Match(input, #"ISA(?<data1>.*?)ESA.ISA(?<data2>.*?)ESA.",RegexOptions.IgnoreCase);
if (match.Success)
{
var data1 = match.Groups["data1"].Value;
var data2 = match.Groups["data2"].Value;
}
Use Regex.Matches If you need multiple matches found, and specify different RegexOptions if needed.
It's kinda hacky but you could do...
string x = "ISA*ESA?ISA*ESA?";
x = x.Replace("*","~"); // OR SOME OTHER DELIMITER
string[] y = x.Split('~');
Not perfect in all situations, but it could solve your problem simply.
You could split by "ISA" and "ESA" and then put the parts back together.
string input = "ISA~this is date~ESA|ISA~this is more data~ESA|";
string start = "ISA",
end = "ESA";
var splitedInput = input.Split(new[] { start, end }, StringSplitOptions.None);
var firstPart = $"{start}{splitedInput[1]}{end}{splitedInput[2]}";
var secondPart = $"{start}{splitedInput[3]}{end}{splitedInput[4]}";
firstPart = "ISA~this is date~ESA|"
secondPart = "ISA~this is more data~ESA|";
Use a Regex like ISA(.+?)ESA and select the first group
string input = "ISA~mycontent+ESA";
Match match = Regex.Match(input, #"ISA(.+?)ESA",RegexOptions.IgnoreCase);
if (match.Success)
{
string key = match.Groups[1].Value;
}
Instead of "splitting" by a string, I would instead describe your question as "grouping" by a string. This can easily be done using a regular expression:
Regular expression: ^(ISA.*?(?=ESA)ESA.)(ISA.*?(?=ESA)ESA.)$
Explanation:
^ - asserts position at start of the string
( - start capturing group
ISA - match string ISA exactly
.*?(?=ESA) - match any character 0 or more times, positive lookahead on the
string ESA (basically match any character until the string ESA is found)
ESA - match string ESA exactly
. - match any character
) - end capturing group
repeat one more time...
$ - asserts position at end of the string
Try it on Regex101
Example:
string input = "ISA~this is date~ESA|ISA~this is more data~ESA|";
Regex regex = new Regex(#"^(ISA.*?(?=ESA)ESA.)(ISA.*?(?=ESA)ESA.)$",
RegexOptions.Compiled);
Match match = regex.Match(input);
if (match.Success)
{
string firstValue = match.Groups[1].Value; // "ISA~this is date~ESA|"
string secondValue = match.Groups[2].Value; // "ISA~this is more data~ESA|"
}
There are two answers to the question "How to split a string by another string".
var matches = input.Split(new [] { "ISA" }, StringSplitOptions.RemoveEmptyEntries);
and
var matches = Regex.Split(input, "ISA").ToList();
However, the first removes empty entries, while the second does not.
Using C#, I have a string that is a SQL script containing multiple queries. I want to remove sections of the string that are enclosed in single quotes. I can do this using Regex.Replace, in this manner:
string test = "Only 'together' can we turn him to the 'dark side' of the Force";
test = Regex.Replace(test, "'[^']*'", string.Empty);
Results in: "Only can we turn him to the of the Force"
What I want to do is remove the substrings between quotes EXCEPT for substrings containing a specific substring. For example, using the string above, I want to remove the quoted substrings except for those that contain "dark," such that the resulting string is:
Results in: "Only can we turn him to the 'dark side' of the Force"
How can this be accomplished using Regex.Replace, or perhaps by some other technique? I'm currently trying a solution that involves using Substring(), IndexOf(), and Contains().
Note: I don't care if the single quotes around "dark side" are removed or not, so the result could also be: "Only can we turn him to the dark side of the Force." I say this because a solution using Split() would remove all the single quotes.
Edit: I don't have a solution yet using Substring(), IndexOf(), etc. By "working on," I mean I'm thinking in my head how this can be done. I have no code, which is why I haven't posted any yet. Thanks.
Edit: VKS's solution below works. I wasn't escaping the \b the first attempt which is why it failed. Also, it didn't work unless I included the single quotes around the whole string as well.
test = Regex.Replace(test, "'(?![^']*\\bdark\\b)[^']*'", string.Empty);
'(?![^']*\bdark\b)[^']*'
Try this.See demo.Replace by empty string.You can use lookahead here to check if '' contains a word dark.
https://www.regex101.com/r/rG7gX4/12
While vks's solution works, I'd like to demonstrate a different approach:
string test = "Only 'together' can we turn him to the 'dark side' of the Force";
test = Regex.Replace(test, #"'[^']*'", match => {
if (match.Value.Contains("dark"))
return match.Value;
// You can add more cases here
return string.Empty;
});
Or, if your condition is simple enough:
test = Regex.Replace(test, #"'[^']*'", match => match.Value.Contains("dark")
? match.Value
: string.Empty
);
That is, use a lambda to provide a callback for the replacement. This way, you can run arbitrary logic to replace the string.
some thing like this would work. you can add all strings you want to keep into the excludedStrings array
string test = "Only 'together' can we turn him to the 'dark side' of the Force";
var excludedString = new string[] { "dark side" };
int startIndex = 0;
while ((startIndex = test.IndexOf('\'', startIndex)) >= 0)
{
var endIndex = test.IndexOf('\'', startIndex + 1);
var subString = test.Substring(startIndex, (endIndex - startIndex) + 1);
if (!excludedString.Contains(subString.Replace("'", "")))
{
test = test.Remove(startIndex, (endIndex - startIndex) + 1);
}
else
{
startIndex = endIndex + 1;
}
}
Another method through regex alternation operator |.
#"('[^']*\bdark\b[^']*')|'[^']*'"
Then replace the matched character with $1
DEMO
string str = "Only 'together' can we turn him to the 'dark side' of the Force";
string result = Regex.Replace(str, #"('[^']*\bdark\b[^']*')|'[^']*'", "$1");
Console.WriteLine(result);
IDEONE
Explanation:
(...) called capturing group.
'[^']*\bdark\b[^']*' would match all the single quoted strings which contains the substring dark . [^']* matches any character but not of ', zero or more times.
('[^']*\bdark\b[^']*'), because the regex is within a capturing group, all the matched characters are stored inside the group index 1.
| Next comes the regex alternation operator.
'[^']*' Now this matches all the remaining (except the one contains dark) single quoted strings. Note that this won't match the single quoted string which contains the substring dark because we already matched those strings with the pattern exists before to the | alternation operator.
Finally replacing all the matched characters with the chars inside group index 1 will give you the desired output.
I made this attempt that I think you were thinking about (some solution using split, Contain, ... without regex)
string test = "Only 'together' can we turn him to the 'dark side' of the Force";
string[] separated = test.Split('\'');
string result = "";
for (int i = 0; i < separated.Length; i++)
{
string str = separated[i];
str = str.Trim(); //trim the tailing spaces
if (i % 2 == 0 || str.Contains("dark")) // you can expand your condition
{
result += str+" "; // add space after each added string
}
}
result = result.Trim(); //trim the tailing space again
I am seeking a way to search a string for an exact match or whole word match. RegEx.Match and RegEx.IsMatch don't seem to get me where I want to be. Consider the following scenario:
namespace test
{
class Program
{
static void Main(string[] args)
{
string str = "SUBTOTAL 34.37 TAX TOTAL 37.43";
int indx = str.IndexOf("TOTAL");
string amount = str.Substring(indx + "TOTAL".Length, 10);
string strAmount = Regex.Replace(amount, "[^.0-9]", "");
Console.WriteLine(strAmount);
Console.WriteLine("Press any key to continue...");
Console.ReadKey();
}
}
}
The output of the above code is:
// 34.37
// Press any key to continue...
The problem is, I don't want SUBTOTAL, but IndexOf finds the first occurrence of the word TOTAL which is in SUBTOTAL which then yields the incorrect value of 34.37.
So the question is, is there a way to force IndexOf to find only an exact match or is there another way to force that exact whole word match so that I can find the index of that exact match and then perform some useful function with it. RegEx.IsMatch and RegEx.Match are, as far as I can tell, simply boolean searches. In this case, it isn't enough to just know the exact match exists. I need to know where it exists in the string.
Any advice would be appreciated.
You can use Regex
string str = "SUBTOTAL 34.37 TAX TOTAL 37.43";
var indx = Regex.Match(str, #"\WTOTAL\W").Index; // will be 18
My method is faster than the accepted answer because it does not use Regex.
string str = "SUBTOTAL 34.37 TAX TOTAL 37.43";
var indx = str.IndexOfWholeWord("TOTAL");
public static int IndexOfWholeWord(this string str, string word)
{
for (int j = 0; j < str.Length &&
(j = str.IndexOf(word, j, StringComparison.Ordinal)) >= 0; j++)
if ((j == 0 || !char.IsLetterOrDigit(str, j - 1)) &&
(j + word.Length == str.Length || !char.IsLetterOrDigit(str, j + word.Length)))
return j;
return -1;
}
You can use word boundaries, \b, and the Match.Index property:
var text = "SUBTOTAL 34.37 TAX TOTAL 37.43";
var idx = Regex.Match(text, #"\bTOTAL\b").Index;
// => 19
See the C# demo.
The \bTOTAL\b matches TOTAL when it is not enclosed with any other letters, digits or underscores.
If you need to count a word as a whole word if it is enclosed with underscores, use
var idx = Regex.Match(text, #"(?<![^\W_])TOTAL(?![^\W_])").Index;
where (?<![^\W_]) is a negative lookbehind that fails the match if there is a character other than a non-word and underscore immediately to the left of the current location (so, there can be a start of string position, or a char that is a not a digit nor letter), and (?![^\W_]) is a similar negative lookahead that only matches if there is an end of string position or a char other than a letter or digit immediately to the right of the current location.
If the boundaries are whitespaces or start/end of string use
var idx = Regex.Match(text, #"(?<!\S)TOTAL(?!\S)").Index;
where (?<!\S) requires start of string or a whitespace immediately on the left, and (?!\S) requires the end of string or a whitespace on the right.
NOTE: \b, (?<!...) and (?!...) are non-consuming patterns, that is the regex index does not advance when matching these patterns, thus, you get the exact positions of the word you search for.
To make the accepted answer a little bit safer (since IndexOf returns -1 for unmatched):
string pattern = String.Format(#"\b{0}\b", findTxt);
Match mtc = Regex.Match(queryTxt, pattern);
if (mtc.Success)
{
return mtc.Index;
}
else
return -1;
While this may be a hack that just works for only your example, try
string amount = str.Substring(indx + " TOTAL".Length, 10);
giving an extra space before total. As this will not occur with SUBTOTAL, it should skip over the word you don't want and just look for an isolated TOTAL.
I'd recommend the Regex solution from L.B. too, but if you can't use Regex, then you could use String.LastIndexOf("TOTAL"). Assuming the TOTAL always comes after SUBTOTAL?
http://msdn.microsoft.com/en-us/library/system.string.lastindexof(v=vs.110).aspx
If I have a string like MCCORMIC 3H R Final 08-26-2011.dwg or even MCCORMIC SMITH 2N L Final 08-26-2011.dwg and I wanted to capture the R in the first string or the L in the second string in a variable, what is the best method for doing so? I was thinking about trying the below statement but it does not work.
string filename = "MCCORMIC 3H R Final 08-26-2011.dwg"
string WhichArea = "";
int WhichIndex = 0;
WhichIndex = filename.IndexOf("Final");
WhichArea = filename.Substring(WhichIndex - 1,1); //Trying to get the R in front of word Final
Just split by space:
var parts = filename.Split(new [] {' '},
StringSplitOptions.RemoveEmptyEntries);
WhichArea = parts[parts.Length - 3];
It looks like the file names have a very specific format, so this will work just fine.
Even with any number of spaces, using StringSplitOptions.RemoveEmptyEntries means spaces will not be part of the split result set.
Code updated to deal with both examples - thanks Nikola.
I had to do something similar, but with Mirostation drawings instead of Autocad. I used regex in my case. Here's what I did, just in case you feel like making it more complex.
string filename = "MCCORMIC 3H R Final 08-26-2011.dwg";
string filename2 = "MCCORMIC SMITH 2N L Final 08-26-2011.dwg";
Console.WriteLine(TheMatch(filename));
Console.WriteLine(TheMatch(filename2));
public string TheMatch(string filename) {
Regex reg = new Regex(#"[A-Za-z0-9]*\s*([A-Z])\s*Final .*\.dwg");
Match match = reg.Match(filename);
if(match.Success) {
return match.Groups[1].Value;
}
return String.Empty;
}
I don't think Oded's answer covers all cases. The first example has two words before the wanted letter, and the second one has three words before it.
My opinion is that the best way to get this letter is by using RegEx, assuming that the word Final always comes after the letter itself, separated by any number of spaces.
Here's the RegEx code:
using System.Text.RegularExpressions;
private string GetLetter(string fileName)
{
string pattern = "\S(?=\s*?Final)";
Match match = Regex.Match(fileName, pattern);
return match.Value;
}
And here's the explanation of RegEx pattern:
\S(?=\s*?Final)
\S // Anything other than whitespace
(?=\s*?Final) // Positive look-ahead
\s*? // Whitespace, unlimited number of repetitions, as few as possible.
Final // Exact text.
Example:
Please make sure you have the connect TNSnames and SQLnet files.
str.SubString(str.IndexOf("connect"));
A combination of IndexOf, SubString and checking that it exists to avoid an ArgumentOutOfRangeException:
string input = "Please make sure you have the connect TNSnames and SQLnet files.";
int index = input.IndexOf("connect");
if (index != -1)
{
string result = input.Substring(index);
}
Also, consider what happens if you have the word "connecting" instead of "connect" - is that a valid partial match or must you find the complete word? If you need the complete word you can use a word-boundary regex by placing your desired word between \b metacharacters:
Match m = Regex.Match(input, #"\bconnect\b.*$");
if (m.Success)
{
Console.WriteLine(m.Value);
}
The .*$ portion tells the regex to match any character (.*) till the end of the sentence ($).
If you really want the index you could omit the .*$ part and use this (although this ignores the usefulness of regex, I am only pointing this out if you need the index for whatever reason):
Match m = Regex.Match(input, #"\bconnect\b");
if (m.Success)
{
int index = m.Index;
Console.WriteLine(input.Substring(index)); // Substring approach again
}
Try the following:
string input = "...";
input.Substring(input.IndexOf("connect"));
Probably Substring.