best possible way to get given substring - c#

lets say I have string in format as below:
[val1].[val2].[val3] ...
What is the best way to get the value from the last bracket set [valx] ?
so for given example
[val1].[val2].[val3]
the result would be val3

You have to define best first, best in terms of readability or cpu-cycles?
I assume this is efficient and readable enough:
string values = "[val1].[val2].[val3]";
string lastValue = values.Split('.').Last().Trim('[',']');
or with Substring which can be more efficient, but it's not as safe since you have to handle the case that's there no dot at all.
lastValue = values.Substring(values.LastIndexOf('.') + 1).Trim('[',']');
So you need to check this first:
int indexOflastDot = values.LastIndexOf('.');
if(indexOflastDot >= 0)
{
lastValue = values.Substring(indexOflastDot + 1).Trim('[',']');
}

For a quick solution to your problem (so not structural),
I'd say:
var startIndex = input.LastIndexOf(".["); // getting the last
then using the Substring method
var value = input.Substring(startIndex + 2, input.Length - (startIndex - 2)); // 2 comes from the length of ".[".
then removing the "]" with TrimEnd function
var value = value.TrimEnd(']');
But this is by all means not the only solution, and not structural to apply.. Just one of many answers to your problem.

I think you want to access the valx.
The easiest solution that comes in my mind is this one:
public void Test()
{
var splitted = "[val1].[val2].[val3]".Split('.');
var val3 = splitted[2];
}

You can use following:
string[] myStrings = ("[val1].[val2].[val3]").Split('.');
Now you can access via index. For last you can use myStrings[myStrings.length - 1]

Providing, that none of val1...valN contains '.', '[' or ']' you can use a simple Linq code:
String str = #"[val1].[val2].[val3]";
String[] vals = str.Split('.').Select((x) => x.TrimStart('[').TrimEnd(']')).ToArray();
Or if all you want is the last value:
String str = #"[val1].[val2].[val3]";
String last = str.Split('.').Last().TrimStart('[').TrimEnd(']');

I'm assuming you always need the last brace. I would do it like this:
string input = "[val1].[val2].[val3]";
string[] splittedInput = input.split('.');
string lastBraceSet = splittedInput[splittedInput.length-1];
string result = lastBraceSet.Substring(1, lastBraceSet.Length - 2);

string str = "[val1].[val2].[val3]";
string last = str.Split('.').LastOrDefault();
string result = last.Replace("[", "").Replace("]", "");

string input="[val1].[val2].[val3]";
int startpoint=input.LastIndexOf("[")+1;
string result=input.Substring(startpoint,input.Length-startpoint-1);

I'd use the below regex. One warning is that it won't work if there are unbalanced square brackets after the last pair of brackets. Most of the answers given suffer from that though.
string s = "[val1].[val2].[val3]"
string pattern = #"(?<=\[)[^\]]+(?=\][^\[\]]*$)"
Match m = Regex.Match(s, pattern)
string result;
if (m.Success)
{
result = m.Value;
}

I would use regular expression, as they are the most clear from intention point of view:
string input = "[val1].[val2].[val3] ...";
string match = Regex.Matches(input, #"\[val\d+\]")
.Cast<Match>()
.Select(m => m.Value)
.Last();

Related

Remove characters between in c#

I have a string values like this
string strValue = "!return.ObjectV,rgmK12D;1.Value";
In this string how can I remove characters from rgm to ;1?
Below code will remove all the characters from rgm, but I need to remove upto ;1 only
strValue = strValue.Substring(0, strValue.LastIndexOf("rgm"));
Expected Result:
string strValue = "!return.ObjectV,.Value";
Edit 1:
I am trying to remove the above mentioned characters from the below string
Sum ({rgmdaerub;1.Total_Value}, {rgmdaerub;1.Major_Value})
Result
Sum ({rgmdaerub;1.Total_Value}, {Major_Value})
Expected Result
Sum ({Total_Value}, {Major_Value})
A simple solution would be:
strValue = strValue.Substring(0, strValue.LastIndexOf("rgm")) + strValue.Substring(strValue.LastIndexOf(";1") + 2);
EDIT:
According to your edit, it seems you want all occurrences replaced. Also, your expected result has the "." removed as well. To replace all occurrences you can adapt from #Damith's answer:
strValue = Regex.Replace(strValue, "rgm.*?;1\\.", "");
with regex
string strValue = "!return.ObjectV,rgmK12D;1.Value";
var output = Regex.Replace(strValue, #" ?rgm.*?;1", string.Empty);
// !return.ObjectV,.Value
One way is to do it like this:
strValue = strValue.Substring(0, strValue.LastIndexOf("rgm")) +
strValue.Substring(strValue.LastIndexOf(";1"), strValue.Length);
This way you get the first part and the second part then concatenate them together. This will work if you have only one instance of these characters.
You can use something like this. First find "rgm" and ";1" position, then remove characters between these indexes.
int start = strValue.LastIndexOf("rgm");
int end = strValue.LastIndexOf(";1");
string str = strValue.Remove(start, (end-start)+2);
You can use string.IndexOf() and string.Replace()
var i = strValue.IndexOf("rgm");
var j = strValue.IndexOf(";1");
var removePart = strValue.Substring(i, j - i);
strValue.Replace(removePart, string.Empty);

Substring IndexOf in c#

I have a string that looks like this: "texthere^D123456_02". But I want my result to be D123456.
this is what i do so far:
if (name.Contains("_"))
{
name = name.Substring(0, name.LastIndexOf('_'));
}
With this I remove at least the _02, however if I try the same way for ^ then I always get back texthere, even when I use name.IndexOf("^")
I also tried only to check for ^, to get at least the result:D123456_02 but still the same result.
I even tried to name.Replace("^" and then use the substring way I used before. But again the result stays the same.
texthere is not always the same length, so .Remove() is out of the question.
What am I doing wrong?
Thanks
When call Substring you should not start from 0, but from the index found:
String name = "texthere^D123456_02";
int indexTo = name.LastIndexOf('_');
if (indexTo < 0)
indexTo = name.Length;
int indexFrom = name.LastIndexOf('^', indexTo - 1);
if (indexFrom >= 0)
name = name.Substring(indexFrom + 1, indexTo - indexFrom - 1);
string s = "texthere^D123456_02";
string result= s.Substring(s.IndexOf("^") + 1);//Remove all before
result = result.Remove(result.IndexOf("_"));//Remove all after
Use the String.Split method :
var split1 = name.Split('^')[1];
var yourText = split1.Split('_')[0];
Or you could use RegExp to achieve basically the same.
Your easiest solution would be to split the string first, and then use your original solution for the second part.
string name = "texthere^D123456_02";
string secondPart = name.Split('^')[1]; // This will be D123456_02
Afterwards you can use the Substring as before.
With Regular Expression
string s = "texthere^D123456_02";
Regex r1 = new Regex(#"\^(.*)_");
MatchCollection mc = r1.Matches(s);
Console.WriteLine("Result is " + mc[0].Groups[1].Value);
An alternative to what's already been suggested is to use regex:
string result = Regex.Match("texthere^D123456_02", #"\^(.*)_").Groups[1].Value; // D123456
use regex.
Regex regex = new Regex(#"\^(.*)_");
Match match = regex.Match(name);
if(match.Success)
{
name= match.Groups[1].Value
}
An easier way would be to use Split
string s = "texthere^D123456_02";
string[] a = s.Split('^', '_');
if (a.Length == 3) // correct
{
}
Well, if you use the same code you posted, it's doing the right thing, you start to retrieve characters from the char 0 and stop when it finds "^", so what you will get is "texthere".
If you want only the value, then use this:
name = name.Substring(0, name.LastIndexOf('_')).Substring(name.IndexOf("^") + 1);
It will first remove whatever is after the "_" and whatever is before "^".
Substring takes a position and a length, so you need to actually figure out where your caret position is and where the underscore is to calculate the length
var name = "texthere^D123456_02";
if(name.Contains('_'))
{
var caretPos = name.IndexOf('^') + 1; // skip ahead
var underscorePos = name.IndexOf('_');
var length = underscorePos - caretPos;
var substring = name.Substring(caretPos, length);
Debug.Print(substring);
};
Try this and let me know how it goes
string inputtext = "texthere^D123456_02";
string pattern = #".+\^([A-Z]+[0-9]+)\_[0-9]+";
string result = Regex.Match(inputtext, pattern).Groups[1].Value;
String name = "texthere^D123456_02"
print name.split('_', '^')[1]
This splits your string at all occurrences of _ and ^ and returns the list of strings after the split. Since the string you need D123456 would be at the 1st index, (i.e. the 2nd position), I have printed out that.
If you are just wanting the "d123456" it's simple with just String.Split() there is no need for anything else. Just define the index you want afterwards. There are overloads on Split() for this very reason.
//...
var source = "texthere^D123456_02";
var result = source.Split(new char[] {'^', '_'}, StringSplitOptions.RemoveEmptyEntries)[1];
Console.WriteLine(result);
//Outputs: "D123456"
Hope this helps.

Split string and string arrays

string s= abc**xy**efg**xy**ijk123**xy**lmxno**xy**opq**xy**rstz;
I want the output as string array, where it get splits at "xy". I used
string[] lines = Regex.Split(s, "xy");
here it removes xy. I want array along with xy. So, after I split my string to string array, array should be as below.
lines[0]= abc;
lines[1]= xyefg;
lines[2]= xyijk123;
lines[3]= xylmxno;
lines[4]= xyopq ;
lines[5]= xyrstz;
how can i do this?
(?=xy)
You need to split on 0 width assertion.See demo.
https://regex101.com/r/fM9lY3/50
string strRegex = #"(?=xy)";
Regex myRegex = new Regex(strRegex, RegexOptions.None);
string strTargetString = #"abcxyefgxyijk123xylmxnoxyopqxyrstz";
return myRegex.Split(strTargetString);
Output:
abc
xyefg
xyijk123
xylmxno
xyopq
xyrstz
It seems fairly simple to do this:
string s = "abc**xy**efg**xy**ijk123**xy**lmxno**xy**opq**xy**rstz";
string[] lines = Regex.Split(s, "xy");
lines = lines.Take(1).Concat(lines.Skip(1).Select(l => "xy" + l)).ToArray();
I get the following result:
I don't know if you wanted to keep the ** - your question doesn't make it clear. Changing the RegEx to #"\*\*xy\*\*" will remove the **.
If you're not married to Regex, you could make your own extension method:
public static IEnumerable<string> Ssplit(this string InputString, string Delimiter)
{
int idx = InputString.IndexOf(Delimiter);
while (idx != -1)
{
yield return InputString.Substring(0, idx);
InputString = InputString.Substring(idx);
idx = InputString.IndexOf(Delimiter, Delimiter.Length);
}
yield return InputString;
}
Usage:
string s = "abc**xy**efg**xy**ijk123**xy**lmxno**xy**opq**xy**rstz";
var x = s.Ssplit("xy");
How about simply looping throgh the array starting with index 1 and adding the "xy" string to each entry?
Alternatively implement your own version of split that cuts the string how you want it.
Yeat another solution would be matching "xy*" in a non-greedy way and your array would be the list of all matches. Depending on language this probably won't be called split BTW.

C# how to pick out certain part in a string

I have a string in a masked TextBox that looks like this:
123.456.789.abc.def.ghi
"---.---.---.---.---.---" (masked TextBox format when empty, cannot use underscore X( )
Please ignore the value of the characters (they can be duplicated, and not unique as above). How can I pick out part of the string, say "789"? String.Remove() does not work, as it removes everything after the index.
You could use Split in order to separate your values if the . is always contained in your string.
string input = "123.456.789.abc.def";
string[] mySplitString = input.Split('.');
for (int i = 0; i < mySplitString.Length; i++)
{
// Do you search part here
}
Do you mean you want to obtain that part of the string? If so, you could use string.Split
string s = "123.456.789.abc.def.ghi";
var splitString = s.Split('.');
// splitString[2] will return "789"
You could simply use String.Split (if the string is actually what you have shown)
string str = "123.456.789.abc.def.ghi";
string[] parts = str.Split('.');
string third = parts.ElementAtOrDefault(2); // zero based index
if(third != null)
Console.Write(third);
I've just used Enumerable.ElementAtOrDefault because it returns null instead of an exception if there's no such index in the collection(It falls back to parts[2]).
Finding a string:
string str="123.456.789.abc.def.ghi";
int i = str.IndexOf("789");
string subStr = str.Substring(i,3);
Replacing the substring:
str = str.Replace("789","").Replace("..",".");
Regex:
str = Regex.Replace(str,"789","");
The regex can give you a lot of flexibility finding things with minimum code, the drawback is it may be difficult to write them
If you know the index of where your substring begins and the length that it will be, you can use String.Substring(). This will give you the substring:
String myString = "123.456.789";
// looking for "789", which starts at index 8 and is length 3
String smallString = myString.Substring(8, 3);
If you are trying to remove a specific part of the string, use String.Replace():
String myString = "123.456.789";
String smallString = myString.Replace("789", "");
var newstr = new String(str.where(c => "789")).tostring();..i guess this would work or you can use sumthng like this
Try using Replace.
String.Replace("789", "")

Extract digit in a string

I have a list of string
goal0=1234.4334abc12423423
goal1=-234234
asdfsdf
I want to extract the number part from string that start with goal,
in the above case is
1234.4334, -234234
(if two fragments of digit get the first one)
how should i do it easily?
Note that "goal0=" is part of the string, goal0 is not a variable.
Therefore I would like to have the first digit fragment that come after "=".
You can do the following:
string input = "goal0=1234.4334abc12423423";
input = input.Substring(input.IndexOf('=') + 1);
IEnumerable<char> stringQuery2 = input.TakeWhile(c => Char.IsDigit(c) || c=='.' || c=='-');
string result = string.Empty;
foreach (char c in stringQuery2)
result += c;
double dResult = double.Parse(result);
Try this
string s = "goal0=-1234.4334abc12423423";
string matches = Regex.Match(s, #"(?<=^goal\d+=)-?\d+(\.\d+)?").Value;
The regex says
(?<=^goal\d+=) - A positive look behind which means look back and make sure goal(1 or more number)= is at the start of the string, but dont make it part of the match
-? - A minus sign which is optional (the ? means 1 or more)
\d+ - One or more digits
(\.\d+)? - A decimal point followed by 1 or more digits which is optional
This will work if your string contains multiple decimal points as well as it will only take the first set of numbers after the first decimal point if there are any.
Use a regex for extracting:
x = Regex.Match(string, #"\d+").Value;
Now convert the resulting string to the number by using:
finalNumber = Int32.Parse(x);
Please try this:
string sample = "goal0=1234.4334abc12423423goal1=-234234asdfsdf";
Regex test = new Regex(#"(?<=\=)\-?\d*(\.\d*)?", RegexOptions.Singleline);
MatchCollection matchlist = test.Matches(sample);
string[] result = new string[matchlist.Count];
if (matchlist.Count > 0)
{
for (int i = 0; i < matchlist.Count; i++)
result[i] = matchlist[i].Value;
}
Hope it helps.
I didn't get the question at first. Sorry, but it works now.
I think this simple expression should work:
Regex.Match(string, #"\d+")
You can use the old VB Val() function from C#. That will extract a number from the front of a string, and it's already available in the framework:
result0 = Microsoft.VisualBasic.Conversion.Val(goal0);
result1 = Microsoft.VisualBasic.Conversion.Val(goal1);
string s = "1234.4334abc12423423";
var result = System.Text.RegularExpressions.Regex.Match(s, #"-?\d+");
List<String> list = new List<String>();
list.Add("goal0=1234.4334abc12423423");
list.Add("goal1=-23423");
list.Add("asdfsdf");
Regex regex = new Regex(#"^goal\d+=(?<GoalNumber>-?\d+\.?\d+)");
foreach (string s in list)
{
if(regex.IsMatch(s))
{
string numberPart = regex.Match(s).Groups["GoalNumber"];
// do something with numberPart
}
}

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