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Comparing string

Is there any method that allow us to return true if string a likes string b formality?
Exam:
"12:2".Like("*:*") = true
or
"what is your name?".Like("*is*name*?")=true
Thanks!

You can use this following function using Regular Expression
Regex.IsMatch("string", "your expression")
Instance following line should return true:
Regex.IsMatch("12:2", "/[0-9]{2,}:[0-9]{1,}/")
Note: This way you have to create exp every time for different format

You can use the following method to check whether a given string matches a DOS like pattern with wildcards (i.e. a pattern that denotes one character with '?' and zero or more characters with '*'):
public static bool IsMatch(string str, string pattern)
{
string regexString = "^" + Regex.Escape(pattern).Replace("\\*", ".*").Replace("\\?", ".") + "$";
Regex regex = new Regex(regexString);
return regex.IsMatch(regexString);
}
You can call it like this:
bool match = IsMatch("what is your name?", "*is*name*?"); // Returns true

You can use the following not-optimized method. The function may does not take into account some cases, but i think it gives you a point to start from.
Another possible solution is to you Regular Expressions
public static bool Like(string pattern, string str)
{
string[] words = pattern.Split('*').Where(w => w.Trim() != string.Empty).ToArray();
List<int> indeces = new List<int>();
for (int i = 0, l = words.Length; i < l; i++)
{
int wordIndex = str.IndexOf(words[i], StringComparison.OrdinalIgnoreCase);
if (wordIndex == -1)
return false;
else
indeces.Add(wordIndex);
}
List<int> sortedIndeces = indeces.ToList();
sortedIndeces.Sort();
for (int i = 0, l = sortedIndeces.Count; i < l; i++)
{
if (sortedIndeces[i] != indeces[i]) return false;
}
return true;
}
Good Luck

How to Get Data from index of String

I'm new in c#. and I have some Question...
I have String following this code
string taxNumber = "1222233333445";
I want to get data from This string like that
string a = "1"
string b = "2222"
string c = "33333"
string d = "44"
string e = "5"
Please Tell me about Method for get Data From String.
Thank You Very Much ^^

Use the String.Substring(int index, int length) method
string a = taxNumber.Substring(0, 1);
string b = taxNumber.Substring(1, 4);
// etc

Oh well, the best I can come up with is this:
IEnumerable<string> numbers
= taxNumber.ToCharArray()
.Distinct()
.Select(c => new string(c, taxNumber.Count(t => t == c)));
foreach (string numberGroup in numbers)
{
Console.WriteLine(numberGroup);
}
Outputs:
1
2222
33333
44
5

This can also do , you dont need to fix the no of characters, you can check by changing the no of 1's , 2's etc
string taxNumber = "1222233333445";
string s1 = taxNumber.Substring(taxNumber.IndexOf("1"), ((taxNumber.Length - taxNumber.IndexOf("1")) - (taxNumber.Length - taxNumber.LastIndexOf("1"))) + 1);
string s2 = taxNumber.Substring(taxNumber.IndexOf("2"), ((taxNumber.Length - taxNumber.IndexOf("2")) - (taxNumber.Length - taxNumber.LastIndexOf("2"))) + 1);
string s3 = taxNumber.Substring(taxNumber.IndexOf("3"), ((taxNumber.Length - taxNumber.IndexOf("3")) - (taxNumber.Length - taxNumber.LastIndexOf("3"))) + 1);

You can use Char.IsDigit to identify digits out of string, and may apply further logic as follows:
for (int i=0; i< taxNumber.Length; i++)
{
if (Char.IsDigit(taxNumber[i]))
{
if(taxNumber[i-1]==taxNumber[i])
{
/*Further assign values*/
}
}

Try this Code
string taxNumber = "1222233333445";
char[] aa = taxNumber.ToCharArray();
List<string> finals = new List<string>();
string temp = string.Empty;
for (int i = 0; i < aa.Length; i++)
{
if (i == 0)
{
temp = aa[i].ToString();
}
else
{
if (aa[i].ToString() == aa[i - 1].ToString())
{
temp += aa[i];
}
else
{
if (temp != string.Empty)
{
finals.Add(temp);
temp = aa[i].ToString();
}
}
if (i == aa.Length - 1)
{
if (aa[i].ToString() != aa[i - 1].ToString())
{
temp = aa[i].ToString();
finals.Add(temp);
}
else
{
finals.Add(temp);
}
}
}
}
and check value of finals string list

you may use regex:
string strRegex = #"(1+|2+|3+|4+|5+|6+|7+|8+|9+|0+)";
RegexOptions myRegexOptions = RegexOptions.None;
Regex myRegex = new Regex(strRegex, myRegexOptions);
string strTargetString = #"1222233333445";
return myRegex.Split(strTargetString);

formatting string in MVC /C#

I have a string 731478718861993983 and I want to get this 73-1478-7188-6199-3983 using C#. How can I format it like this ?
Thanks.

By using regex:
public static string FormatTest1(string num)
{
string formatPattern = #"(\d{2})(\d{4})(\d{4})(\d{4})(\d{4})";
return Regex.Replace(num, formatPattern, "$1-$2-$3-$4-$5");
}
// test
string test = FormatTest1("731478718861993983");
// test result: 73-1478-7188-6199-3983

If you're dealing with a long number, you can use a NumberFormatInfo to format it:
First, define your NumberFormatInfo (you may want additional parameters, these are the basic 3):
NumberFormatInfo format = new NumberFormatInfo();
format.NumberGroupSeparator = "-";
format.NumberGroupSizes = new[] { 4 };
format.NumberDecimalDigits = 0;
Next, you can use it on your numbers:
long number = 731478718861993983;
string formatted = number.ToString("n", format);
Console.WriteLine(formatted);
After all, .Net has very good globalization support - you're better served using it!

string s = "731478718861993983"
var newString = (string.Format("{0:##-####-####-####-####}", Convert.ToInt64(s));

LINQ-only one-liner:
var str = "731478718861993983";
var result =
new string(
str.ToCharArray().
Reverse(). // So that it will go over string right-to-left
Select((c, i) => new { #char = c, group = i / 4}). // Keep group number
Reverse(). // Restore original order
GroupBy(t => t.group). // Now do the actual grouping
Aggregate("", (s, grouping) => "-" + new string(
grouping.
Select(gr => gr.#char).
ToArray())).
ToArray()).
Trim('-');
This can handle strings of arbitrary lenghs.

Simple (and naive) extension method :
class Program
{
static void Main(string[] args)
{
Console.WriteLine("731478718861993983".InsertChar("-", 4));
}
}
static class Ext
{
public static string InsertChar(this string str, string c, int i)
{
for (int j = str.Length - i; j >= 0; j -= i)
{
str = str.Insert(j, c);
}
return str;
}
}

If you're dealing strictly with a string, you can make a simple Regex.Replace, to capture each group of 4 digits:
string str = "731478718861993983";
str = Regex.Replace(str, "(?!^).{4}", "-$0" ,RegexOptions.RightToLeft);
Console.WriteLine(str);
Note the use of RegexOptions.RightToLeft, to start capturing from the right (so "12345" will be replaced to 1-2345, and not -12345), and the use of (?!^) to avoid adding a dash in the beginning.
You may want to capture only digits - a possible pattern then may be #"\B\d{4}".

string myString = 731478718861993983;
myString.Insert(2,"-");
myString.Insert(7,"-");
myString.Insert(13,"-");
myString.Insert(18,"-");

My first thought is:
String s = "731478718861993983";
s = s.Insert(3,"-");
s = s.Insert(8,"-");
s = s.Insert(13,"-");
s = s.Insert(18,"-");
(don't remember if index is zero-based, in which case you should use my values -1)
but there is probably some easier way to do this...

If the position of "-" is always the same then you can try
string s = "731478718861993983";
s = s.Insert(2, "-");
s = s.Insert(7, "-");
s = s.Insert(12, "-");
s = s.Insert(17, "-");

Here's how I'd do it; it'll only work if you're storing the numbers as something which isn't a string as they're not able to be used with format strings.
string numbers = "731478718861993983";
string formattedNumbers = String.Format("{0:##-####-####-####-####}", long.Parse(numbers));
Edit: amended code, since you said they were held as a string in your your original question

how do i convert string numbers to int

I want just numbers.
string str_a = "a1bc2d23ghj2";
int in_b = convert.toint32(str_a); // doesn't works
I want the output of in_b to be: 12232

string str_a = "a1bc2d23ghj2";
string str_digits_only = new String(str_a.Where(char.IsDigit).ToArray());
int in_b = Convert.ToInt32(str_digits_only);

StringBuilder builder = new StringBuilder();
foreach (char c in str_a)
{
if (Char.IsDigit(c))
{
builder.Append(c);
}
}
int in_b = Int32.Parse(builder.ToString());

It doesn't work because the input string is not a valid number and also because you have to use Convert.ToInt32(string) or int.Parse(string).
If you want to extract only the numbers from a string you could use LINQ:
string onlyNumbers = (from ch in str_a
where char.IsDigit(ch)
select ch.ToString()).Aggregate((a, b) => a + b);
int in_b = int.Parse(onlyNumbers);

my solution for this would be to check the char codes of the characters in your string. Select all numbers and convert them:
var str_a = "a1bc2d23ghj2";
var in_b = Convert.ToInt32(string.Join(string.Empty,str_a.Where(x => x >= 48 && x <= 57)));

int num = Convert.ToInt(System.Text.Regex.Replace(stra, "[^0-9]", string.Empty));

Have a look at the tryparse method.

How do I remove all non alphanumeric characters from a string except dash?

How do I remove all non alphanumeric characters from a string except dash and space characters?

Replace [^a-zA-Z0-9 -] with an empty string.
Regex rgx = new Regex("[^a-zA-Z0-9 -]");
str = rgx.Replace(str, "");

I could have used RegEx, they can provide elegant solution but they can cause performane issues. Here is one solution
char[] arr = str.ToCharArray();
arr = Array.FindAll<char>(arr, (c => (char.IsLetterOrDigit(c)
|| char.IsWhiteSpace(c)
|| c == '-')));
str = new string(arr);
When using the compact framework (which doesn't have FindAll)
Replace FindAll with1
char[] arr = str.Where(c => (char.IsLetterOrDigit(c) ||
char.IsWhiteSpace(c) ||
c == '-')).ToArray();
str = new string(arr);
1 Comment by ShawnFeatherly

You can try:
string s1 = Regex.Replace(s, "[^A-Za-z0-9 -]", "");
Where s is your string.

Using System.Linq
string withOutSpecialCharacters = new string(stringWithSpecialCharacters.Where(c =>char.IsLetterOrDigit(c) || char.IsWhiteSpace(c) || c == '-').ToArray());

The regex is [^\w\s\-]*:
\s is better to use instead of space (), because there might be a tab in the text.

Based on the answer for this question, I created a static class and added these. Thought it might be useful for some people.
public static class RegexConvert
{
public static string ToAlphaNumericOnly(this string input)
{
Regex rgx = new Regex("[^a-zA-Z0-9]");
return rgx.Replace(input, "");
}
public static string ToAlphaOnly(this string input)
{
Regex rgx = new Regex("[^a-zA-Z]");
return rgx.Replace(input, "");
}
public static string ToNumericOnly(this string input)
{
Regex rgx = new Regex("[^0-9]");
return rgx.Replace(input, "");
}
}
Then the methods can be used as:
string example = "asdf1234!##$";
string alphanumeric = example.ToAlphaNumericOnly();
string alpha = example.ToAlphaOnly();
string numeric = example.ToNumericOnly();

Want something quick?
public static class StringExtensions
{
public static string ToAlphaNumeric(this string self,
params char[] allowedCharacters)
{
return new string(Array.FindAll(self.ToCharArray(),
c => char.IsLetterOrDigit(c) ||
allowedCharacters.Contains(c)));
}
}
This will allow you to specify which characters you want to allow as well.

Here is a non-regex heap allocation friendly fast solution which was what I was looking for.
Unsafe edition.
public static unsafe void ToAlphaNumeric(ref string input)
{
fixed (char* p = input)
{
int offset = 0;
for (int i = 0; i < input.Length; i++)
{
if (char.IsLetterOrDigit(p[i]))
{
p[offset] = input[i];
offset++;
}
}
((int*)p)[-1] = offset; // Changes the length of the string
p[offset] = '\0';
}
}
And for those who don't want to use unsafe or don't trust the string length hack.
public static string ToAlphaNumeric(string input)
{
int j = 0;
char[] newCharArr = new char[input.Length];
for (int i = 0; i < input.Length; i++)
{
if (char.IsLetterOrDigit(input[i]))
{
newCharArr[j] = input[i];
j++;
}
}
Array.Resize(ref newCharArr, j);
return new string(newCharArr);
}

I´ve made a different solution, by eliminating the Control characters, which was my original problem.
It is better than putting in a list all the "special but good" chars
char[] arr = str.Where(c => !char.IsControl(c)).ToArray();
str = new string(arr);
it´s simpler, so I think it´s better !

Here's an extension method using #ata answer as inspiration.
"hello-world123, 456".MakeAlphaNumeric(new char[]{'-'});// yields "hello-world123456"
or if you require additional characters other than hyphen...
"hello-world123, 456!?".MakeAlphaNumeric(new char[]{'-','!'});// yields "hello-world123456!"
public static class StringExtensions
{
public static string MakeAlphaNumeric(this string input, params char[] exceptions)
{
var charArray = input.ToCharArray();
var alphaNumeric = Array.FindAll<char>(charArray, (c => char.IsLetterOrDigit(c)|| exceptions?.Contains(c) == true));
return new string(alphaNumeric);
}
}

If you are working in JS, here is a very terse version
myString = myString.replace(/[^A-Za-z0-9 -]/g, "");

I use a variation of one of the answers here. I want to replace spaces with "-" so its SEO friendly and also make lower case. Also not reference system.web from my services layer.
private string MakeUrlString(string input)
{
var array = input.ToCharArray();
array = Array.FindAll<char>(array, c => char.IsLetterOrDigit(c) || char.IsWhiteSpace(c) || c == '-');
var newString = new string(array).Replace(" ", "-").ToLower();
return newString;
}

There is a much easier way with Regex.
private string FixString(string str)
{
return string.IsNullOrEmpty(str) ? str : Regex.Replace(str, "[\\D]", "");
}