Test string:
the%20matrix%20
How can I delete the last three chars? Using this code gives me an out of index exception:
y = y.Substring(y.Length - 4, y.Length - 1);
Seems this isn't your REAL problem; if you want to remove that "%20", you should use:
string test = "the%20matrix%20";
string clean = HttpUtility.UrlDecode(test);
if (clean.Length > 2) // if you still want to strip last chars...
clean = clean.Substring(0, clean.Length - 3);
As dalovega said, you need the first parameter of Substring to be 0 and the second Length - 3. As an alternative:
if(y.Length >= 3)
{
y = y.Remove(y.Length - 3)
}
You want
y.Substring(0, y.Length-4)
If you want to delete the last three characters, you need the first parameter of your Substring method to be zero.
You need to check that the string is at least 3 characters long first.
if (y.Length > 2)
{
}
As others have said the version of Substring you want parameters are startIndex and length.
Though what do you want to do with 1 or 2 character strings?
I found this post from a search I was looking for. I had a delimiter I was building with a string builder, and concat and wanted to remove the last delimiter.
var delim = "{somedelimiter}";
var sb = new StringBuilder();
//concat the values into one string
foreach (var val in values)
{
sb.Append(val);
sb.Append(delim);
}
var finalValue = sb.ToString();
finalValue = finalValue.Remove(finalValue.Length - delim.Length);
string.Remove(string.LastIndexOf(" stringTo "));
Related
I have this code:
string firstTag = "Forums2008/forumPage.aspx?forumId=";
string endTag = "</a>";
index = forums.IndexOf(firstTag, index1);
if (index == -1)
continue;
var secondIndex = forums.IndexOf(endTag, index);
result = forums.Substring(index + firstTag.Length + 12, secondIndex - (index + firstTag.Length - 50));
The string i want to extract from is for example:
הנקה
What i want to get is the word after the title only this: הנקה
And the second problem is that when i'm extracting it i see instead hebrew some gibrish like this: ������
One powerful way to do this is to use Regular Expressions instead of trying to find a starting position and use a substring. Try out this code, and you'll see that it extracts the anchor tag's title:
var input = "הנקה";
var expression = new System.Text.RegularExpressions.Regex(#"title=\""([^\""]+)\""");
var match = expression.Match(input);
if (match.Success) {
Console.WriteLine(match.Groups[1]);
}
else {
Console.WriteLine("not found");
}
And for the curious, here is a version in JavaScript:
var input = 'הנקה';
var expression = new RegExp('title=\"([^\"]+)\"');
var results = expression.exec(input);
if (results) {
document.write(results[1]);
}
else {
document.write("not found");
}
Okay here is the solution using String.Substring() String.Split() and String.IndexOf()
String str = "הנקה"; // <== Assume this is passing string. Yes unusual scape sequence are added
int splitStart = str.IndexOf("title="); // < Where to start splitting
int splitEnd = str.LastIndexOf("</a>"); // < = Where to end
/* What we try to extract is this : title="הנקה">הנקה
* (Given without escape sequence)
*/
String extracted = str.Substring(splitStart, splitEnd - splitStart); // <=Extracting required portion
String[] splitted = extracted.Split('"'); // < = Now split with "
Console.WriteLine(splitted[1]); // <= Try to Out but yes will produce ???? But put a breakpoint here and check the values in split array
Now the problem, here you can see that i have to use escape sequence in an unusual way. You may ignore that since you are simply passing the scanning string.
And this actually works, but you cannot visualize it with the provided Console.WriteLine(splitted[1]);
But if you put a break point and check the extracted split array you can see that text are extracted. you can confirm it with following screenshot
I use WinForms c#.I have string value like below,
string Something = "1,5,12,34,";
I need to remove last comma in a string. So How can i delete it ?
Try string.TrimEnd():
Something = Something.TrimEnd(',');
King King's answer is of course correct, and Tim Schmelter's comment is also good suggestion in your case.
But if you really want to remove the last comma in a string, you should find the index of the last comma and remove it like this:
string s = "1,5,12,34,12345";
int index = s.LastIndexOf(',');
Console.WriteLine(s.Remove(index, 1));
Output will be:
1,5,12,3412345
Here is a demonstration.
It is unlikely that you want this way but I want to point it out. And remember, the String.Remove method doesn't remove any characters in the original string, it returns new string.
Try string.Remove();
string str = "1,5,12,34,";
string removecomma = str.Remove(str.Length-1);
MessageBox.Show(removecomma);
The TrimEnd method takes an input character array and not a string.
The code below from Dot Net Perls, shows a more efficient example of how to perform the same functionality as TrimEnd.
static string TrimTrailingChars(string value)
{
int removeLength = 0;
for (int i = value.Length - 1; i >= 0; i--)
{
char let = value[i];
if (let == '?' || let == '!' || let == '.')
{
removeLength++;
}
else
{
break;
}
}
if (removeLength > 0)
{
return value.Substring(0, value.Length - removeLength);
}
return value;
}
Dim psValue As String = "1,5,12,34,123,12"
psValue = psValue.Substring(0, psValue.LastIndexOf(","))
output:
1,5,12,34,123
Try below
Something..TrimEnd(",".ToCharArray());
Or you can convert it into Char Array first by:
string Something = "1,5,12,34,";
char[] SomeGoodThing=Something.ToCharArray[];
Now you have each character indexed:
SomeGoodThing[0] -> '1'
SomeGoodThing[1] -> ','
Play around it
When you have spaces at the end. you can use beliow.
ProcessStr = ProcessStr.Replace(" ", "");
Emails = ProcessStr.TrimEnd(';');
Try this,
string Something1= Something.Substring(0, Something.Length - 1 );
I have a file called file_test1.txt and I want to extract just test1 from the name and place it in a string. Whats the best way of doing this?
E.g.
string fullfile = #"C:\file_test1.txt";
string section = [test1] from fullfile; // <- expected result
I want to be able to split on 'file_' and '.txt' as the 'test1' section could be larger or smaller however the 'file_' and '.txt' will always be the same.
Try Path.GetFileNameWithoutExtension(fullfile).Substring(5) (or Substring("TEMPLATE_PREFIX".Length))
You can try spilt
var test = Path.GetFileNameWithoutExtension(fullfile).split('_')[1];
Try following
string fullfile = #"C:\file_test1.txt";
var name = fullfile.Substring(8,fullfile.Length-12)
As c:\file_ and .txt are fixed, You can take Substring starting at index 8 (skip leading name), upto length of total string length - 12 (12 => length of leading name, and trailing extension)
Thought I'd give a solution that uses Split and handles files with multiple underscores:
string.Join("_", Path.GetFileNameWithoutExtension(file).Split('_').Skip(1));
String.Split() works quite well for my uses:
http://msdn.microsoft.com/en-us/library/b873y76a.aspx
Obviously many ways to accomplish this. Here's yet another approach:
string fullfile = #"C:\file_test1.txt";
int index1 = fullfile.LastIndexOf("file_");
if (index1 != -1)
{
int index2 = fullfile.IndexOf(".", index1);
if (index2 != -1)
{
string section = fullfile.Substring(index1 + 5, index2 - index1 - 5);
}
}
You could also get "test1", or any subsequent filename (assuming your file naming convention remains constant!) using this regular expression:
var defaultRegex = new Regex(#"(?<=_).*(?=.txt)");
var matches = defaultRegex.Matches(fullfile);
var match = matches[0].Value;
The regular expression:
(?<=_).*(?=.txt)
uses positive look behind to find text preceded by '_', and also positive lookahead to find text which has '.txt' ahead of it.
How can I get "MyLibrary.Resources.Images.Properties" and "Condo.gif" from a "MyLibrary.Resources.Images.Properties.Condo.gif" string.
I also need it to be able to handle something like "MyLibrary.Resources.Images.Properties.legend.House.gif" and return "House.gif" and "MyLibrary.Resources.Images.Properties.legend".
IndexOf LastIndexOf wouldn't work because I need the second to last '.' character.
Thanks in advance!
UPDATE
Thanks for the answers so far but I really need it to be able to handle different namespaces. So really what I'm asking is how to I split on the second to last character in a string?
You can use LINQ to do something like this:
string target = "MyLibrary.Resources.Images.Properties.legend.House.gif";
var elements = target.Split('.');
const int NumberOfFileNameElements = 2;
string fileName = string.Join(
".",
elements.Skip(elements.Length - NumberOfFileNameElements));
string path = string.Join(
".",
elements.Take(elements.Length - NumberOfFileNameElements));
This assumes that the file name part only contains a single . character, so to get it you skip the number of remaining elements.
You can either use a Regex or String.Split with '.' as the separator and return the second-to-last + '.' + last pieces.
You can look for IndexOf("MyLibrary.Resources.Images.Properties."), add that to MyLibrary.Resources.Images.Properties.".Length and then .Substring(..) from that position
If you know exactly what you're looking for, and it's trailing, you could use string.endswith. Something like
if("MyLibrary.Resources.Images.Properties.Condo.gif".EndsWith("Condo.gif"))
If that's not the case check out regular expressions. Then you could do something like
if(Regex.IsMatch("Condo.gif"))
Or a more generic way: split the string on '.' then grab the last two items in the array.
string input = "MyLibrary.Resources.Images.Properties.legend.House.gif";
//if string isn't already validated, make sure there are at least two
//periods here or you'll error out later on.
int index = input.LastIndexOf('.', input.LastIndexOf('.') - 1);
string first = input.Substring(0, index);
string second = input.Substring(index + 1);
Try splitting the string into an array, by separating it by each '.' character.
You will then have something like:
{"MyLibrary", "Resources", "Images", "Properties", "legend", "House", "gif"}
You can then take the last two elements.
Just break down and do it in a char loop:
int NthLastIndexOf(string str, char ch, int n)
{
if (n <= 0) throw new ArgumentException();
for (int idx = str.Length - 1; idx >= 0; --idx)
if (str[idx] == ch && --n == 0)
return idx;
return -1;
}
This is less expensive than trying to coax it using string splitting methods and isn't a whole lot of code.
string s = "1.2.3.4.5";
int idx = NthLastIndexOf(s, '.', 3);
string a = s.Substring(0, idx); // "1.2"
string b = s.Substring(idx + 1); // "3.4.5"
I have a string "8329874566".
I want to place - in the string like this "832-98-4566"
Which string function can I use?
I would have done something like this..
string value = "8329874566";
value = value.Insert(6, "-").Insert(3, "-");
You convert it to a number and then format the string.
What I like most about this is it's easier to read/understand what's going on then using a few substring methods.
string str = "832984566";
string val = long.Parse(str).ToString("###-##-####");
There may be a tricky-almost-unreadable regex solution, but this one is pretty readable, and easy.
The first parameter of the .Substring() method is where you start getting the characters, and the second is the number of characters you want to get, and not giving it sets a default as value.length -1 (get chars until the end of the string):
String value = "8329874566";
String Result = value.Substring(0,3) + "-" + value.Substring(3,2) + "-" + value.Substring(6);
--[edit]--
Just noticed you didn't use one of the numbers AT ALL (number '7') in the expected result example you gave, but if you want it, just change the last substring as "5", and if you want the '7' but don't want 5 numbers in the last set, let it like "5,4".
Are you trying to do this like American Social Security numbers? I.e., with a hyphen after the third and and fifth numerals? If so:
string s = "8329874566";
string t = String.Format("{0}-{1}-{2}", s.Substring(0, 3), s.Substring(3, 2), s.Substring(5));
Just out of completeness, a regular expression variant:
Regex.Replace(s, #"(\d{3})(\d{2})(\d{4})", "$1-$2-$3");
I consider the Insert variant to be the cleanest, though.
This works fine, and I think that is more clear:
String value = "8329874566";
value = value.Insert(3, "-").Insert(6, "-");
The console outputs shows this:
832-98-74566
If the hyphens are to go in the same place each time, then you could simply concatenate together the pieces of the orginal string like this:
// 0123456789 <- index
string number = "8329874566";
string new = number.Substring(0, 3) + "-" + number.Substring(3, 2) + "-" + number.Substring(5);
For a general way of making mutable strings, use the StringBuilder class. This allows deletions and insertions to be made before calling ToString to produce the final string.
You could try the following:
string strNumber = "8329874566"
string strNewNumber = strNumber.Substring(0,3) + "-" + strNumber.Substring(4,2) + "-" strNumber.Substring(6)
or something in this manner
string val = "832984566";
string result = String.Format("{0}-{1}-{2}", val.Substring(0,3), val.Substring(3,2), val.Substring(5,4));
var result = string.Concat(value.Substring(0,3), "-", value.Substring(3,2), "-", value.Substring(5,4));
or
var value = "8329874566".Insert(3, "-").Insert(6, "-");
Now how about this for a general solution?
// uglified code to fit within horizontal limits
public static string InsertAtIndices
(this string original, string insertion, params int[] insertionPoints) {
var mutable = new StringBuilder(original);
var validInsertionPoints = insertionPoints
.Distinct()
.Where(i => i >= 0 && i < original.Length)
.OrderByDescending(i => i);
foreach (int insertionPoint in validInsertionPoints)
mutable.Insert(insertionPoint, insertion);
return mutable.ToString();
}
Usage:
string ssn = "832984566".InsertAtIndices("-", 3, 5);
string crazy = "42387542342309856340924803"
.InsertAtIndices(":", 1, 2, 3, 4, 5, 6, 17, 200, -1, -1, 2, 3, 3, 4);
Console.WriteLine(ssn);
Console.WriteLine(crazy);
Output:
832-98-4566
4:2:3:8:7:5:42342309856:340924803
Overkill? Yeah, maybe...
P.S. Yes, I am regex illiterate--something I hope to rectify someday.
A straightforward (but not flexible) approach would be looping over the characters of the string while keeping a counter running. You can then construct a new string character by character. You can add the '-' character after the 3rd and 5th character.
A better approach may be to use a function to insert a single character in the middle of the string at a specific index. String.Insert() would do well. The only thing to pay attention to here is that the string indexes will get off by one with each insert.
EDIT more language-specific as per comments