How to remove leading zeros using C# - c#

How to remove leading zeros in strings using C#?
For example in the following numbers, I would like to remove all the leading zeros.
0001234
0000001234
00001234

This is the code you need:
string strInput = "0001234";
strInput = strInput.TrimStart('0');

It really depends on how long the NVARCHAR is, as a few of the above (especially the ones that convert through IntXX) methods will not work for:
String s = "005780327584329067506780657065786378061754654532164953264952469215462934562914562194562149516249516294563219437859043758430587066748932647329814687194673219673294677438907385032758065763278963247982360675680570678407806473296472036454612945621946";
Something like this would
String s ="0000058757843950000120465875468465874567456745674000004000".TrimStart(new Char[] { '0' } );
// s = "58757843950000120465875468465874567456745674000004000"

Code to avoid returning an empty string ( when input is like "00000").
string myStr = "00012345";
myStr = myStr.TrimStart('0');
myStr = myStr.Length > 0 ? myStr : "0";

return numberString.TrimStart('0');

Using the following will return a single 0 when input is all 0.
string s = "0000000"
s = int.Parse(s).ToString();

TryParse works if your number is less than Int32.MaxValue. This also gives you the opportunity to handle badly formatted strings. Works the same for Int64.MaxValue and Int64.TryParse.
int number;
if(Int32.TryParse(nvarchar, out number))
{
// etc...
number.ToString();
}

This Regex let you avoid wrong result with digits which consits only from zeroes "0000" and work on digits of any length:
using System.Text.RegularExpressions;
/*
00123 => 123
00000 => 0
00000a => 0a
00001a => 1a
00001a => 1a
0000132423423424565443546546356546454654633333a => 132423423424565443546546356546454654633333a
*/
Regex removeLeadingZeroesReg = new Regex(#"^0+(?=\d)");
var strs = new string[]
{
"00123",
"00000",
"00000a",
"00001a",
"00001a",
"0000132423423424565443546546356546454654633333a",
};
foreach (string str in strs)
{
Debug.Print(string.Format("{0} => {1}", str, removeLeadingZeroesReg.Replace(str, "")));
}
And this regex will remove leading zeroes anywhere inside string:
new Regex(#"(?<!\d)0+(?=\d)");
// "0000123432 d=0 p=002 3?0574 m=600"
// => "123432 d=0 p=2 3?574 m=600"

Regex rx = new Regex(#"^0+(\d+)$");
rx.Replace("0001234", #"$1"); // => "1234"
rx.Replace("0001234000", #"$1"); // => "1234000"
rx.Replace("000", #"$1"); // => "0" (TrimStart will convert this to "")
// usage
var outString = rx.Replace(inputString, #"$1");

I just crafted this as I needed a good, simple way.
If it gets to the final digit, and if it is a zero, it will stay.
You could also use a foreach loop instead for super long strings.
I just replace each leading oldChar with the newChar.
This is great for a problem I just solved, after formatting an int into a string.
/* Like this: */
int counterMax = 1000;
int counter = ...;
string counterString = counter.ToString($"D{counterMax.ToString().Length}");
counterString = RemoveLeadingChars('0', ' ', counterString);
string fullCounter = $"({counterString}/{counterMax})";
// = ( 1/1000) ... ( 430/1000) ... (1000/1000)
static string RemoveLeadingChars(char oldChar, char newChar, char[] chars)
{
string result = "";
bool stop = false;
for (int i = 0; i < chars.Length; i++)
{
if (i == (chars.Length - 1)) stop = true;
if (!stop && chars[i] == oldChar) chars[i] = newChar;
else stop = true;
result += chars[i];
}
return result;
}
static string RemoveLeadingChars(char oldChar, char newChar, string text)
{
return RemoveLeadingChars(oldChar, newChar, text.ToCharArray());
}
I always tend to make my functions suitable for my own library, so there are options.

Related

Extract number from string value

I have a string that always come into this format:
"TM" + multiple Leading 0 + Number + Non-Number Character + Alphanumeric.
For example: TM000013452S20548, PB000013452S3DVSF.
How do I parse (in C# code) the varchar value to get the "Number" (13452) in this case?
You can use RegualarExpressions:
(?:TM|PB)0{0,}(\d+)
Like this:
string input = "For example: TM000013452S20548, PB000013452S3DVSF.";
var matches = Regex.Matches(input, #"(?:TM|PB)0{0,}(\d+)");
foreach(Match m in matches)
Console.WriteLine(int.Parse(m.Groups[1].Value));
Live Demo
You can use Linq:
var number = new String(
yourString.Skip(2)
.SkipWhile(s => s == '0')
.TakeWhile(s => Char.IsDigit(s))
.ToArray()
);
If all the fields are fixed width, and all you care about is the first integer, then it's pretty easy; just use string.Substring to extract the part you care about and then parse it.
Here's how to do the extract and parse (note that I use int.TryParse - you are parsing a possibly corrupted string):
private bool TryExtractFirstNumber(string input, out int result)
{
var resultString = input.Substring(2, 9);
return int.TryParse(resultString, out result);
}
You can call this like:
var inputs = new[]
{
"TM000013452S20548",
"PB000013452S3DVSF",
};
foreach (var inp in inputs)
{
if (TryExtractFirstNumber(inp, out var result))
{
Debug.WriteLine(result);
}
}
The output from that is:
13452
13452
If the position of the "Non-Number Character" that you describe is not known, go looking for it:
private int FindIndexOfFirstNonNumeric(string toScan, int startIndex = 0)
{
for (var index = startIndex; index < toScan.Length; ++index)
{
if (!char.IsNumber(toScan[index]))
{
return index;
}
}
return toScan.Length;
}
and then modify the TryExtractFirstNumber function to look for it:
private bool TryExtractFirstNumber(string input, out int result)
{
var length = FindIndexOfFirstNonNumeric(input, 2) - 2;
var resultString = input.Substring(2, length);
return int.TryParse(resultString, out result);
}
It gives the same results.

Get a range from two integers

string num = db.SelectNums(id);
string[] numArr = num.Split('-').ToArray();
string num contain for an example "48030-48039";
string[] numArr will therefor contain (48030, 48039).
Now I have two elements, a high and low. I now need to get ALL the numbers from 48030 to 48039. The issue is that it has to be string since there will be telephone numbers with leading zeroes now and then.
Thats why I cannot use Enumerable.Range().ToArray() for this.
Any suggestions? The expected result should be 48030, 48031, 48032, ... , 48039
This should work with your leading zero requirement:
string num = db.SelectNums(id);
string[] split = num.Split('-');
long start = long.Parse(split[0]);
long end = long.Parse(split[1]);
bool includeLeadingZero = split[0].StartsWith("0");
List<string> results = new List<string>();
for(int i = start; i <= end; i++)
{
string result = includeLeadingZero ? "0" : "";
result += i.ToString();
results.Add(result);
}
string[] arrayResults = results.ToArray();
A few things to note:
It assumes your input will be 2 valid integers split by a single hyphen
I am giving you a string array result, personally I would prefer to work with a List<int> in the end
If the first number contains a single leading zero, then all results will contain a single leading zero
It uses long to cater for longer numbers, beware that the max number that will parse is 9,223,372,036,854,775,807, you could double this value (not length) by using ulong
Are you saying this?
int[] nums = new int[numArr.Length];
for (int i = 0; i < numArr.Length; i++)
{
nums[i] = Convert.ToInt32(numArr[i]);
}
Array.Sort(nums);
for (int n = nums[0]; n <= nums[nums.Length - 1]; n++)
{
Console.WriteLine(n);
}
here link
I am expecting your string always have valid two integers, so using Parse instead TryParse
string[] strList = "48030-48039".Split('-').ToArray();
var lst = strList.Select(int.Parse).ToList();
var min = lst.OrderBy(l => l).FirstOrDefault();
var max = lst.OrderByDescending(l => l).FirstOrDefault();
var diff = max - min;
//adding 1 here otherwise 48039 will not be there
var rng = Enumerable.Range(min,diff+1);
If you expecting invalid string
var num = 0;
var lst = (from s in strList where int.TryParse(s, out num) select num).ToList();
This is one way to do it:
public static string[] RangeTest()
{
Boolean leadingZero = false;
string num = "048030-48039"; //db.SelectNums(id);
if (num.StartsWith("0"))
leadingZero = true;
int min = int.Parse(num.Split('-').Min());
int count = int.Parse(num.Split('-').Max()) - min;
if (leadingZero)
return Enumerable.Range(min, count).Select(x => "0" + x.ToString()).ToArray();
else
return Enumerable.Range(min, count).Select(x => "" + x.ToString()).ToArray(); ;
}
You can use string.Format to ensure numbers are formatted with leading zeros. That will make the method work with arbitrary number of leading zeros.
private static string CreateRange(string num)
{
var tokens = num.Split('-').Select(s => s.Trim()).ToArray();
// use UInt64 to allow huge numbers
var start = UInt64.Parse(tokens[0]);
var end = UInt64.Parse(tokens[1]);
// if your start number is '000123', this will create
// a format string with 6 zeros ('000000')
var format = new string('0', tokens[0].Length);
// use StringBuilder to make GC happy.
// (if only there was a Enumerable.Range<ulong> overload...)
var sb = new StringBuilder();
for (var i = start; i <= end; i++)
{
// format ensures that your numbers are padded properly
sb.Append(i.ToString(format));
sb.Append(", ");
}
// trim trailing comma after the last element
if (sb.Length >= 2) sb.Length -= 2;
return sb.ToString();
}
Usage example:
// prints 0000012, 0000013, 0000014
Console.WriteLine( CreateRange("0000012-0000014") );
Three significant issues were brought up in comments:
The phone numbers have enough digits to exceed Int32.MaxValue so
converting to int isn't viable.
The phone numbers can have leading zeros (presumeably for some
international calling?)
The possible range of numbers can theoretically exceed the maximum size of an array (which may have memory issues, and I think may not be represented as a string)
As such, you may need to use long instead of int, and I would suggest using deferred execution if needed for very large ranges.
public static IEnumerable<string> EnumeratePhoneNumbers(string fromAndTo)
{
var split = fromAndTo.Split('-');
return EnumeratePhoneNumbers(split[0], split[1]);
}
public static IEnumerable<string> EnumeratePhoneNumbers(string fromString, string toString)
{
long from = long.Parse(fromString);
long to = long.Parse(toString);
int totalNumberLength = fromString.Length;
for (long phoneNumber = from; phoneNumber <= to; phoneNumber++)
{
yield return phoneNumber.ToString().PadLeft(totalNumberLength, '0');
}
}
This assumes that the padded zeros are already included in the lower bound fromString text. It will iterate and yield out numbers as you need them. This can be useful if you're churning out a lot of numbers and don't need to fill up memory with them, or if you just need the first 10 or 100. For example:
var first100Numbers =
EnumeratePhoneNumbers("0018155500-7018155510")
.Take(100)
.ToArray();
Normally that range would produce 7 billion results which cannot be stored in an array, and might run into memory issues (I'm not even sure if it can be stored in a string); by using deferred execution, you only create the 100 needed.
If you do have a small range, you can still join up your results into a string as you desired:
string numberRanges = String.Join(", ", EnumeratePhoneNumbers("0018155500-0018155510"));
And naturally you can put this array creation into your own helper method:
public static string GetPhoneNumbersListing(string fromAndTo)
{
return String.Join(", ", EnumeratePhoneNumbers("0018155500-0018155510"));
}
So your usage would be:
string numberRanges = GetPhoneNumbersListing("0018155500-0018155510");
A complete solution inspired by the answer by #Dan-o:
Inputs:
Start: 48030
End: 48039
Digits: 6
Expected String Output:
048030, 048031, 048032, 048033, 048034, 048035, 048036, 048037, 048038, 048039
Program:
using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
public class Program
{
public static void Main()
{
int first = 48030;
int last = 48039;
int digits = 6;
Console.WriteLine(CreateRange(first, last, digits));
}
public static string CreateRange(int first, int last, int numDigits)
{
string separator = ", ";
var sb = new StringBuilder();
sb.Append(first.ToString().PadLeft(numDigits, '0'));
foreach (int num in Enumerable.Range(first + 1, last - first))
{
sb.Append(separator + num.ToString().PadLeft(numDigits, '0'));
}
return sb.ToString();
}
}
For Each item In Enumerable.Range(min, count).ToArray()
something = item.PadLeft(5, "0")
Next

How to Return true if String array having mix of Int and String type value converted to int in C#

I have string which I split to see if any of the split value is string. If so I want to return true else false.
string words = "1 2 c 5";
Easy approach, I can follow by converting into int array and then compare value side by side.
int[] iar = words.Split(' ').Select(s => int.TryParse(s, out n) ? n : 0).ToArray();
Can any one recommend better approach?
You can simply check without using Split:
var result = words.Any(c => !char.IsWhiteSpace(c)
&& !char.IsDigit(c));
Or using Split:
var result = words.Split()
.Any(w => w.Any(c => !char.IsDigit(c)));
The point is you can use char.IsDigit to check instead of using int.Parse or int.TryParse.
You could do this with a simple little method:
public static bool CheckForNum(string[] wordsArr)
{
int i = 0;
foreach (string s in wordsArr)
{
if (Int32.TryParse(s, out i))
{
return true;
}
}
return false;
}
Using:
bool result = CheckForNum(words.Split(' '));
Console.Write(result);
Why not use a regular expression? If a string has words and numbers in it, it must have letters and number characters. I don't entirely understand the logic in your question, so you may need to adjust the logic here.
using System;
using System.Text.RegularExpressions;
...
string words = "1 2 c 5";
Match numberMatch = Regex.Match(words, #"[0-9]", RegexOptions.IgnoreCase);
Match letterMatch = Regex.Match(words, #"[a-zA-Z]", RegexOptions.IgnoreCase);
// Here we check the Match instance.
if (numberMatch.Success && letterMatch.Success)
{
// there are letters and numbers
}

Add separator to string at every N characters?

I have a string which contains binary digits. How to separate string after each 8 digit?
Suppose the string is:
string x = "111111110000000011111111000000001111111100000000";
I want to add a separator like ,(comma) after each 8 character.
output should be :
"11111111,00000000,11111111,00000000,11111111,00000000,"
Then I want to send it to a list<> last 8 char 1st then the previous 8 chars(excepting ,) and so on.
How can I do this?
Regex.Replace(myString, ".{8}", "$0,");
If you want an array of eight-character strings, then the following is probably easier:
Regex.Split(myString, "(?<=^(.{8})+)");
which will split the string only at points where a multiple of eight characters precede it.
Try this:
var s = "111111110000000011111111000000001111111100000000";
var list = Enumerable
.Range(0, s.Length/8)
.Select(i => s.Substring(i*8, 8));
var res = string.Join(",", list);
There's another Regex approach:
var str = "111111110000000011111111000000001111111100000000";
# for .NET 4
var res = String.Join(",",Regex.Matches(str, #"\d{8}").Cast<Match>());
# for .NET 3.5
var res = String.Join(",", Regex.Matches(str, #"\d{8}")
.OfType<Match>()
.Select(m => m.Value).ToArray());
...or old school:
public static List<string> splitter(string in, out string csv)
{
if (in.length % 8 != 0) throw new ArgumentException("in");
var lst = new List<string>(in/8);
for (int i=0; i < in.length / 8; i++) lst.Add(in.Substring(i*8,8));
csv = string.Join(",", lst); //This we want in input order (I believe)
lst.Reverse(); //As we want list in reverse order (I believe)
return lst;
}
Ugly but less garbage:
private string InsertStrings(string s, int insertEvery, char insert)
{
char[] ins = s.ToCharArray();
int length = s.Length + (s.Length / insertEvery);
if (ins.Length % insertEvery == 0)
{
length--;
}
var outs = new char[length];
long di = 0;
long si = 0;
while (si < s.Length - insertEvery)
{
Array.Copy(ins, si, outs, di, insertEvery);
si += insertEvery;
di += insertEvery;
outs[di] = insert;
di ++;
}
Array.Copy(ins, si, outs, di, ins.Length - si);
return new string(outs);
}
String overload:
private string InsertStrings(string s, int insertEvery, string insert)
{
char[] ins = s.ToCharArray();
char[] inserts = insert.ToCharArray();
int insertLength = inserts.Length;
int length = s.Length + (s.Length / insertEvery) * insert.Length;
if (ins.Length % insertEvery == 0)
{
length -= insert.Length;
}
var outs = new char[length];
long di = 0;
long si = 0;
while (si < s.Length - insertEvery)
{
Array.Copy(ins, si, outs, di, insertEvery);
si += insertEvery;
di += insertEvery;
Array.Copy(inserts, 0, outs, di, insertLength);
di += insertLength;
}
Array.Copy(ins, si, outs, di, ins.Length - si);
return new string(outs);
}
If I understand your last requirement correctly (it's not clear to me if you need the intermediate comma-delimited string or not), you could do this:
var enumerable = "111111110000000011111111000000001111111100000000".Batch(8).Reverse();
By utilizing morelinq.
Here my two little cents too. An implementation using StringBuilder:
public static string AddChunkSeparator (string str, int chunk_len, char separator)
{
if (str == null || str.Length < chunk_len) {
return str;
}
StringBuilder builder = new StringBuilder();
for (var index = 0; index < str.Length; index += chunk_len) {
builder.Append(str, index, chunk_len);
builder.Append(separator);
}
return builder.ToString();
}
You can call it like this:
string data = "111111110000000011111111000000001111111100000000";
string output = AddChunkSeparator(data, 8, ',');
One way using LINQ:
string data = "111111110000000011111111000000001111111100000000";
const int separateOnLength = 8;
string separated = new string(
data.Select((x,i) => i > 0 && i % separateOnLength == 0 ? new [] { ',', x } : new [] { x })
.SelectMany(x => x)
.ToArray()
);
I did it using Pattern & Matcher as following way:
fun addAnyCharacter(input: String, insertion: String, interval: Int): String {
val pattern = Pattern.compile("(.{$interval})", Pattern.DOTALL)
val matcher = pattern.matcher(input)
return matcher.replaceAll("$1$insertion")
}
Where:
input indicates Input string. Check results section.
insertion indicates Insert string between those characters. For example comma (,), start(*), hash(#).
interval indicates at which interval you want to add insertion character.
input indicates Input string. Check results section. Check results section; here I've added insertion at every 4th character.
Results:
I/P: 1234XXXXXXXX5678 O/P: 1234 XXXX XXXX 5678
I/P: 1234567812345678 O/P: 1234 5678 1234 5678
I/P: ABCDEFGHIJKLMNOP O/P: ABCD EFGH IJKL MNOP
Hope this helps.
As of .Net 6, you can simply use the IEnumerable.Chunk method (Which splits elements of a sequence into chunks) then reconcatenate the chunks using String.Join.
var text = "...";
string.Join(',', text.Chunk(size: 6).Select(x => new string(x)));
This is much faster without copying array (this version inserts space every 3 digits but you can adjust it to your needs)
public string GetString(double valueField)
{
char[] ins = valueField.ToString().ToCharArray();
int length = ins.Length + (ins.Length / 3);
if (ins.Length % 3 == 0)
{
length--;
}
char[] outs = new char[length];
int i = length - 1;
int j = ins.Length - 1;
int k = 0;
do
{
if (k == 3)
{
outs[i--] = ' ';
k = 0;
}
else
{
outs[i--] = ins[j--];
k++;
}
}
while (i >= 0);
return new string(outs);
}
For every 1 character, you could do this one-liner:
string.Join(".", "1234".ToArray()) //result: 1.2.3.4
If you intend to create your own function to acheive this without using regex or pattern matching methods, you can create a simple function like this:
String formatString(String key, String seperator, int afterEvery){
String formattedKey = "";
for(int i=0; i<key.length(); i++){
formattedKey += key.substring(i,i+1);
if((i+1)%afterEvery==0)
formattedKey += seperator;
}
if(formattedKey.endsWith("-"))
formattedKey = formattedKey.substring(0,formattedKey.length()-1);
return formattedKey;
}
Calling the mothod like this
formatString("ABCDEFGHIJKLMNOPQRST", "-", 4)
Would result in the return string as this
ABCD-EFGH-IJKL-MNOP-QRST
A little late to the party, but here's a simplified LINQ expression to break an input string x into groups of n separated by another string sep:
string sep = ",";
int n = 8;
string result = String.Join(sep, x.InSetsOf(n).Select(g => new String(g.ToArray())));
A quick rundown of what's happening here:
x is being treated as an IEnumerable<char>, which is where the InSetsOf extension method comes in.
InSetsOf(n) groups characters into an IEnumerable of IEnumerable -- each entry in the outer grouping contains an inner group of n characters.
Inside the Select method, each group of n characters is turned back into a string by using the String() constructor that takes an array of chars.
The result of Select is now an IEnumerable<string>, which is passed into String.Join to interleave the sep string, just like any other example.
I am more than late with my answer but you can use this one:
static string PutLineBreak(string str, int split)
{
for (int a = 1; a <= str.Length; a++)
{
if (a % split == 0)
str = str.Insert(a, "\n");
}
return str;
}

Format string with dashes

I have a compressed string value I'm extracting from an import file. I need to format this into a parcel number, which is formatted as follows: ##-##-##-###-###. So therefore, the string "410151000640" should become "41-01-51-000-640". I can do this with the following code:
String.Format("{0:##-##-##-###-###}", Convert.ToInt64("410151000640"));
However, The string may not be all numbers; it could have a letter or two in there, and thus the conversion to the int will fail. Is there a way to do this on a string so every character, regardless of if it is a number or letter, will fit into the format correctly?
Regex.Replace("410151000640", #"^(.{2})(.{2})(.{2})(.{3})(.{3})$", "$1-$2-$3-$4-$5");
Or the slightly shorter version
Regex.Replace("410151000640", #"^(..)(..)(..)(...)(...)$", "$1-$2-$3-$4-$5");
I would approach this by having your own formatting method, as long as you know that the "Parcel Number" always conforms to a specific rule.
public static string FormatParcelNumber(string input)
{
if(input.length != 12)
throw new FormatException("Invalid parcel number. Must be 12 characters");
return String.Format("{0}-{1}-{2}-{3}-{4}",
input.Substring(0,2),
input.Substring(2,2),
input.Substring(4,2),
input.Substring(6,3),
input.Substring(9,3));
}
This should work in your case:
string value = "410151000640";
for( int i = 2; i < value.Length; i+=3){
value = value.Insert( i, "-");
}
Now value contains the string with dashes inserted.
EDIT
I just now saw that you didn't have dashes between every second number all the way, to this will require a small tweak (and makes it a bit more clumsy also I'm afraid)
string value = "410151000640";
for( int i = 2; i < value.Length-1; i+=3){
if( value.Count( c => c == '-') >= 3) i++;
value = value.Insert( i, "-");
}
If its part of UI you can use MaskedTextProvider in System.ComponentModel
MaskedTextProvider prov = new MaskedTextProvider("aa-aa-aa-aaa-aaa");
prov.Set("41x151000a40");
string result = prov.ToDisplayString();
Here is a simple extension method with some utility:
public static string WithMask(this string s, string mask)
{
var slen = Math.Min(s.Length, mask.Length);
var charArray = new char[mask.Length];
var sPos = s.Length - 1;
for (var i = mask.Length - 1; i >= 0 && sPos >= 0;)
if (mask[i] == '#') charArray[i--] = s[sPos--];
else
charArray[i] = mask[i--];
return new string(charArray);
}
Use it as follows:
var s = "276000017812008";
var mask = "###-##-##-##-###-###";
var dashedS = s.WithMask(mask);
You can use it with any string and any character other than # in the mask will be inserted. The mask will work from right to left. You can tweak it to go the other way if you want.
Have fun.
If i understodd you correctly youre looking for a function that removes all letters from a string, aren't you?
I have created this on the fly, maybe you can convert it into c# if it's what you're looking for:
Dim str As String = "410151000vb640"
str = String.Format("{0:##-##-##-###-###}", Convert.ToInt64(MakeNumber(str)))
Public Function MakeNumber(ByVal stringInt As String) As String
Dim sb As New System.Text.StringBuilder
For i As Int32 = 0 To stringInt.Length - 1
If Char.IsDigit(stringInt(i)) Then
sb.Append(stringInt(i))
End If
Next
Return sb.ToString
End Function

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