Develop Reference

How can I add an integer to an existing record?

Please be kind enough to tell me how I can add an integer to an existing record which starts with a string sequence like the following;
S0000 - S00027
Kind Regards,
Indunil Sanjeewa

Try this code:
string record = "S00009";
string recordPrefix = "S";
char paddingCharacter = '0';
string recordNoPart = record.Substring(recordPrefix.Length);
int nextRecordNo = int.Parse(recordNoPart) + 1;
string nextRecord = string.Format("{0}{1}", recordPrefix, nextRecordNo.ToString().PadLeft(record.Length - recordPrefix.Length, paddingCharacter));
#kurakura88 has already given the logic. I have just provided the hardcore c# code.

The logic is:
separate the "S00009" into "S" and "00009". Use string method Substring()
Parse "00009" into integer. Use Int.Parse or Int.TryParse
Add 1 into the integer
Print back the "S" and the integer. Use string.Concat or simply string + integer

You can use following approach
string input = #"S0000";
string pattern = #"\d+";
string format = #"0000";
int addend = 1;
string result = Regex.Replace(input, pattern,
m => (int.Parse(m.Value) + addend).ToString(format));
// result = S0001
Regular expression \d+ matches all digits.
MatchEvaluator converts matched value to integer. Then adds the addend. Then converts the value to a string using the specified format.
In the end using the Replace method replaces the previous value with the new value.

Number increment from string value

I my application due to some reason I have two numbers in 5 digits.
The following code give you brief idea.
string s = "00001"; // Initially stored somewhere.
//Operation start
string id = DateTime.Now.ToString("yy") + DateTime.Now.AddYears(-1).ToString("yy") + s;
//Operation end
//Increment the value of s by 1. i.e 00001 to 00002
This can be done easily by convert the value of s to int and increment it by 1 but after all that I have to also store the incremented value of s in 5 digit so it will be "00002".
This think give me a pain...

use
string s = "00001";
int number = Convert.ToInt32(s);
number += 1;
string str = number.ToString("D5");
to get atleast 5 digits.
The "D" (or decimal) format specifier
If required, the number is padded with zeros to its left to produce the number of digits given by the precision specifier. If no
precision specifier is specified, the default is the minimum value
required to represent the integer without leading zeros.

This seems to work for me.
string s = "00001";
int i = Int32.Parse(s);
i++;
s = i.ToString("D" + s.Length);

So I think you want to know how to convert an int to a 5 digit string.
You can do this:
int i = 1;
string s = i.ToString("D5");
//s = "00001"
There are plenty of format examples here.

Use String.Format() to achieve this:
string str = String.Format({0:#####}, s);
Look here.

This works using the PadLeft function:
int i = 1; // Initially stored somewhere.
//Operation start
string id = DateTime.Now.ToString("yy") + DateTime.Now.AddYears(-1).ToString("yy") + i.ToString().PadLeft(5, '0');
//Operation end

How to split a string based on every third character regardless of what the character is in c# [duplicate]

This question already has answers here:
Closed 10 years ago.
Possible Duplicate:
.NET String.Format() to add commas in thousands place for a number
I am trying to add commas to a number for the presentation layer and need to cast and then split the number on every third character in order to join on a ','.
So if i have a string like this
546546555
desired output:
546,546,555
Other times, the number could be longer or shorter:
254654
desired output:
254,654
Is it possible to split in this manner then join with a comma?
tahnks!
EDIT:
Hi Everyone,
Thanks very much for your help.
To add to this post I also found a way to do this in SQL:
SUBSTRING(CONVERT(varchar, CAST(NumItems AS money), 1), 0, LEN(CONVERT(varchar, CAST(NumDocs AS money), 1)) - 2) as [NumDocs]

Rather than splitting the string manually, you should convert it to a number (or leave it as a number), and call the ToString method with the appropriate formatting:
Example
int value = 546546555;
string displayValue = value.ToString("#,#");
See this MSDN page for different format values:
C - Currency format
D - Decimal format
E - Scientific format
F - Fixed point format
G - General format
N - Number format
P - Percent format
R - Round trip format
X - Hexadecimal format

You should do this by converting your string to an integer, using Parse or ideally TryParse and use string formatting to display it:
var str = "546546555";
var formatted = String.Empty;
int value = 0;
if(int.TryParse(str,out value))
{
formatted = value.ToString("#,#");
}
Live example: http://rextester.com/FHO11833

Assuming you aren't only trying to output numbers, here's a quick function that I believe would do what you are after:
string splitter(string tosplit, int num, string splitstring)
{
string output = "";
for (int i = 0; i < tosplit.Length; i += num)
if (i + num < tosplit.Length)
output += tosplit.Substring(i, num) + ",";
else
output += tosplit.Substring(i);
return output;
}
Here, the output of splitter("546546555", 3, ",") would be 546,546,555
This would not be ideal for numbers though, as the other answers would cover this case perfectly.

Not very good code, but it works.
public static string GetString(string val, int number)
{
List<string> res = new List<string>();
res.Add("");
int counter = 0, i = 0;
while (i < val.Length)
{
while (res[counter].Length < number && i < val.Length)
{
res[counter] += val[i];
i++;
}
res.Add("");
counter++;
}
return string.Join(",", res.Where(r => !string.IsNullOrEmpty(r)));
}
val - your input string
number - number of characters you want to split, equals to 3 in your case

Gene S and Dan seem to have the answer IMHO. The nice thing about using the built in formatting is that you can write localizable code. For example, the "," is the numeric group separator in the US, but the "." is used in Spain.
var val = 12345678;
CultureInfo c = CultureInfo.CurrentCulture;
Application.CurrentCulture = new CultureInfo("EN-us");
var s = String.Format("{0:#,#}", val);
Application.CurrentCulture = new CultureInfo("ES-es");
var i = String.Format("{0:#,#}", val);
Application.CurrentCulture = c;

C# , Substring How to access last elements of an array/string using substring

I am generating 35 strings which have the names ar15220110910, khwm20110910 and so on.
The string contains the name of the Id (ar152,KHWM), and the date (20110910). I want to extract the Id, date from the string and store it in a textfile called StatSummary.
My code statement is something like this
for( int 1= 0;i< filestoextract.count;1++)
{
// The filestoextract contains 35 strings
string extractname = filestoextract(i).ToString();
statSummary.writeline( extractname.substring(0,5) + "" +
extractname.substring(5,4) + "" + extractname.substring(9,2) + "" +
extractname.substring(11,2));
}
When the station has Id containing 5 letters, then this code executes correctly but when the station Id is KHWM or any other 4 letter name then the insertion is all messed up. I am running this inside a loop. So I have tried keeping the code as dynamic as possible. Could anyone help me to find a way without hardcoding it. For instance accessing the last 8 elements to get the date??? I have searched but am not able to find a way to do that.

For the last 8 digits, it's just:
extractname.Substring(extractname.Length-8)
oh, I'm sorry, and so for your code could be:
int l = extractname.Length;
statSummary.WriteLine(extractname.substring(0,l-8) + "" +
extractname.Substring(l-8,4) + "" + extractname.Substring(l-4,2) + "" +
extractname.Substring(l-2,2));

As your ID length isn't consistent, it would probably be a better option to extract the date (which is always going to be 8 chars) and then treat the remainder as your ID e.g.
UPDATED - more robust by actually calculating the length of the date based on the format. Also validates against the format to make sure you have parsed the data correctly.
var dateFormat = "yyyyMMdd"; // this could be pulled from app.config or some other config source
foreach (var file in filestoextract)
{
var dateStr = file.Substring(file.Length-dateFormat.Length);
if (ValidateDate(dateStr, dateFormat))
{
var id = file.Substring(0, file.Length - (dateFormat.Length+1));
// do something with data
}
else
{
// handle invalid filename
}
}
public bool ValidateDate(stirng date, string date_format)
{
try
{
DateTime.ParseExact(date, date_format, DateTimeFormatInfo.InvariantInfo);
}
catch
{
return false;
}
return true;
}

You could use a Regex :
match = Regex.Match ("khwm20110910","(?<code>.*)(?<date>.{6})" );
Console.WriteLine (match.Groups["code"] );
Console.WriteLine (match.Groups["date"] );
To explain the regex pattern (?<code>.*)(?<date>.{6}) the brackets groups creates a group for each pattern. ?<code> names the group so you can reference it easily.
The date group takes the last six characters of the string. . says take any character and {6} says do that six times.
The code group takes all the remaining characters. * says take as many characters as possible.

for each(string part in stringList)
{
int length = part.Length;
int start = length - 8;
string dateString = part.Substring(start, 8);
}
That should solve the variable length to get the date. The rest of the pull is most likely dependent on a pattern (suggested) or the length of string (when x then the call is 4 in length, etc)

If you ID isn't always the same amount of letters you should seperate the ID and the Date using ',' or somthing then you use this:
for( int 1= 0;i< filestoextract.count;1++)
{
string extractname = filestoextract[i].ToString();
string ID = extractname.substring(0, extractname.IndexOf(','));
string Date = extractname.substring(extractname.IndexOf(','));
Console.WriteLine(ID + Date);
}

How to delete characters and append strings?

I am adding a new record to XML file, first I'm querying all existing items and storing the count in an int
int number = query.count()
and then increment the number by 1.
number = number + 1;
Now I want to format this value in a string having N00000000 format
and the number will occupy the last positions.
Pseudo code:
//declare the format string
sting format = "N00000000"
//calculate the length of number string
int length =number.ToString().Length();
// delete as many characters from right to left as the length of number string
???
// finally concatenate both strings with + operator
???

String output = "N" + String.Format ("00000000", length)
Alternatively if you change your formatstring to "'N'00000000" you can even use:
String output = String.Format (formatString, length)
Which means you can fully specify your output by changing your formatstring without having to change any code.

int i = 123;
string n = "N" + i.ToString().PadLeft(8, '0');

var result = number.ToString("N{0:0000000}");
HTH

You can use the built in ToString overload that takes a custom numeric format string:
string result = "N" + number.ToString("00000000");

Here is a another one ...
result = String.Format("N{0:00000000}",number);