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Splitting string value c#

I want to know about how to splitting a value in string format in to two parts. Here in my asp application I'm parsing string value from view to controller.
And then I want to split the whole value in to two parts.
Example like: Most of the times value firest two letters could be TEXT value (like "PO" , "SS" , "GS" ) and the rest of the others are numbers (SS235452).
The length of the numbers cannot declare, since it generates randomly. So Want to split it from the begining of the string value. Need a help for that.
My current code is
string approvalnumber = approvalCheck.ApprovalNumber.ToUpper();
Thanks.

As you already mentioned that first part will have 2 letters and it's only second part which is varying, you can use Substring Method of String as shown below.
var textPart = input.Substring(0,2);
var numPart = input.Substring(2);
The first line fetches 2 characters from starting index zero and the second statement fetches all characters from index 2. You can cast the second part to a number if required.
Please note that the second parameter of Substring is not mentioned in second line. This parameter is for length and if nothing is mentioned it fetches till end of string.

You could try using regex to extract alpha, numbers from the string.
This javascript function returns only numbers from the input string.
function getNumbers(input) {
return input.match(/[0-9]+/g);
}

I'd use a RegExp. Considering the fact that you indicate ASP-NET-4 I assume you can't use tuples, out var etc. so it'd go as follows:
using System.Text.RegularExpressions;
using FluentAssertions;
using Xunit;
namespace Playground
{
public class Playground
{
public struct ProjectCodeMatch
{
public string Code { get; set; }
public int? Number { get; set; }
}
[Theory]
[InlineData("ABCDEFG123", "ABCDEFG", 123)]
[InlineData("123456", "", 123456)]
[InlineData("ABCDEFG", "ABCDEFG", null)]
[InlineData("ab123", "AB", 123)]
public void Split_Works(string input, string expectedCode, int? expectedNumber)
{
ProjectCodeMatch result;
var didParse = TryParse(input, out result);
didParse.Should().BeTrue();
result.Code.Should().Be(expectedCode);
result.Number.Should().Be(expectedNumber);
}
private static bool TryParse(string input, out ProjectCodeMatch result)
{
/*
* A word on this RegExp:
* ^ - the match must happen at the beginning of the string (nothing before that)
* (?<Code>[a-zA-Z]+) - grab any number of letters and name this part the "Code" group
* (?<Number>\d+) - grab any number of numbers and name this part the Number group
* {0,1} this group must occur at most 1 time
* $ - the match must end at the end of the string (nothing after that)
*/
var regex = new Regex(#"^(?<Code>[a-zA-Z]+){0,1}(?<Number>\d+){0,1}$");
var match = regex.Match(input);
if (!match.Success)
{
result = default;
return false;
}
int number;
var isNumber = int.TryParse(match.Groups["Number"].Value, out number);
result = new ProjectCodeMatch
{
Code = match.Groups["Code"].Value.ToUpper(),
Number = isNumber ? number : null
};
return true;
}
}
}

A linq answer:
string d = "PO1232131";
string.Join("",d.TakeWhile(a => Char.IsLetter(a)))

Reverse the letter case in a string using List

I don't understand where is my mistake, and would appreciate help. I would like to reverse the letter case in a string and return reversed chars to the List using List.Add() method.
using System.Linq;
using System.Collections.Generic;
using System;
public class Program
{
public static string ReverseCase(string str)
{
List<char> result = new List<char>();
foreach(char pew in str){
char.IsUpper(pew) ? result.Add(Char.ToLower(pew)):result.Add(Char.ToUpper(pew));
}
return result.ToString();
}
}

There are two issues here - first, the usage of the ? operator - you can't use code blocks there, just values. So instead of using it with two Add calls, you can use it to get the correct value within an Add call.
Second, calling ToString() on a List won't do what you expect it to do. You could, however, join the characters in the list to get a string:
public static string ReverseCase(string str)
{
List<char> result = new List<char>();
foreach(char pew in str){
result.Add(char.IsUpper(pew) ? Char.ToLower(pew) : Char.ToUpper(pew));
}
return String.Join("", result);
}

Get the char first and add it to the list, like this approach :
public static string ReverseCase(string str)
{
List<char> result = new List<char>();
foreach (char pew in str)
{
result.Add(char.IsUpper(pew) ? char.ToLower(pew) : char.ToUpper(pew));
}
return new string(result.ToArray());
}
Note that, result.ToString() can't convert list of char to string.
I hope you find this helpful.

C# Splitting another string

I am wanting to split the next string which is "L" but it is not working for some reason. I have managed to make this work for my first substring and it seems to be working but this is not working for my second substring which should return "L" within the console in a new line or the 20th character. Any ideas?
using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
namespace employeefinal
{
class Program
{
static void Main(string[] args)
{
employee i = new employee();
Console.WriteLine(i.getName());
Console.ReadLine();
Console.WriteLine(i.getCity());
Console.ReadLine();
}
public class employee
{
string employeename = "Name:John How Smith L, U, 012, 2, 7, 2, 4";
public employee()
{
}
public string getName()
{
return employeename.Substring(0, 19).Trim();
}
public string getCity()
{
return employeename.Substring(19, 20).Trim();
}
}
}
}

With Substring the second parameter is the length of the substring. If you just want getCity to return 'L' you could change it to:
return employeename.Substring(20,1).Trim();

Substring() method accepts two things one is character position and length from that position. In your code GetName() returns starting from zero position to 19th position and in 2nd method ie GetCity() returns from 19th position to rest of character in that string. So substring(19,2) will work I guess.

Enum and string match

I'm essentially trying to read an xml file. One of the values has a suffix, e.g. "30d". This is meant to mean '30 days'. So I'm trying to convert this to a DateTime.Now.AddDays(30). To read this field in the XML, i decided to use an Enum:
enum DurationType { Min = "m", Hours = "h", Days = "d" }
Now I'm not exactly sure how exactly to approach this efficiently (I'm a little daft when it comes to enums). Should I separate the suffix, in this case "d", out of the string first, then try and match it in the enum using a switch statement?
I guess if you dumb down my question, it'd be: What's the best way to get from 30d, to DateTime.Now.AddDays(30) ?

You could make an ExtensionMethod to parse the string and return the DateTime you want
Something like:
public static DateTime AddDuration(this DateTime datetime, string str)
{
int value = 0;
int mutiplier = str.EndsWith("d") ? 1440 : str.EndsWith("h") ? 60 : 1;
if (int.TryParse(str.TrimEnd(new char[]{'m','h','d'}), out value))
{
return datetime.AddMinutes(value * mutiplier);
}
return datetime;
}
Usage:
var date = DateTime.Now.AddDuration("2d");

This seems like a good place to use regular expressions; specifically, capture groups.
Below is a working example:
using System;
using System.Text.RegularExpressions;
namespace RegexCaptureGroups
{
class Program
{
// Below is a breakdown of this regular expression:
// First, one or more digits followed by "d" or "D" to represent days.
// Second, one or more digits followed by "h" or "H" to represent hours.
// Third, one or more digits followed by "m" or "M" to represent minutes.
// Each component can be separated by any number of spaces, or none.
private static readonly Regex DurationRegex = new Regex(#"((?<Days>\d+)d)?\s*((?<Hours>\d+)h)?\s*((?<Minutes>\d+)m)?", RegexOptions.IgnoreCase);
public static TimeSpan ParseDuration(string input)
{
var match = DurationRegex.Match(input);
var days = match.Groups["Days"].Value;
var hours = match.Groups["Hours"].Value;
var minutes = match.Groups["Minutes"].Value;
int daysAsInt32, hoursAsInt32, minutesAsInt32;
if (!int.TryParse(days, out daysAsInt32))
daysAsInt32 = 0;
if (!int.TryParse(hours, out hoursAsInt32))
hoursAsInt32 = 0;
if (!int.TryParse(minutes, out minutesAsInt32))
minutesAsInt32 = 0;
return new TimeSpan(daysAsInt32, hoursAsInt32, minutesAsInt32, 0);
}
static void Main(string[] args)
{
Console.WriteLine(ParseDuration("30d"));
Console.WriteLine(ParseDuration("12h"));
Console.WriteLine(ParseDuration("20m"));
Console.WriteLine(ParseDuration("1d 12h"));
Console.WriteLine(ParseDuration("5d 30m"));
Console.WriteLine(ParseDuration("1d 12h 20m"));
Console.WriteLine("Press any key to exit.");
Console.ReadKey();
}
}
}
EDIT: Below is an alternative, slightly more condensed version of the above, though I'm not sure which one I prefer more. I'm usually not a fan of overly dense code.
I adjusted the regular expression to put a limit of 10 digits on each number. This allows me to safely use the int.Parse function, because I know that the input consists of at least one digit and at most ten (unless it didn't capture at all, in which case it would be empty string: hence, the purpose of the ParseInt32ZeroIfNullOrEmpty method).
// Below is a breakdown of this regular expression:
// First, one to ten digits followed by "d" or "D" to represent days.
// Second, one to ten digits followed by "h" or "H" to represent hours.
// Third, one to ten digits followed by "m" or "M" to represent minutes.
// Each component can be separated by any number of spaces, or none.
private static readonly Regex DurationRegex = new Regex(#"((?<Days>\d{1,10})d)?\s*((?<Hours>\d{1,10})h)?\s*((?<Minutes>\d{1,10})m)?", RegexOptions.IgnoreCase);
private static int ParseInt32ZeroIfNullOrEmpty(string input)
{
return string.IsNullOrEmpty(input) ? 0 : int.Parse(input);
}
public static TimeSpan ParseDuration(string input)
{
var match = DurationRegex.Match(input);
return new TimeSpan(
ParseInt32ZeroIfNullOrEmpty(match.Groups["Days"].Value),
ParseInt32ZeroIfNullOrEmpty(match.Groups["Hours"].Value),
ParseInt32ZeroIfNullOrEmpty(match.Groups["Minutes"].Value),
0);
}
EDIT: Just to take this one more step, I've added another version below, which handles days, hours, minutes, seconds, and milliseconds, with a variety of abbreviations for each. I split the regular expression into multiple lines for readability. Note, I also had to adjust the expression by using (\b|(?=[^a-z])) at the end of each component: this is because the "ms" unit was being captured as the "m" unit. The special syntax of "?=" used with "[^a-z]" indicates to match the character but not to "consume" it.
// Below is a breakdown of this regular expression:
// First, one to ten digits followed by "d", "dy", "dys", "day", or "days".
// Second, one to ten digits followed by "h", "hr", "hrs", "hour", or "hours".
// Third, one to ten digits followed by "m", "min", "minute", or "minutes".
// Fourth, one to ten digits followed by "s", "sec", "second", or "seconds".
// Fifth, one to ten digits followed by "ms", "msec", "millisec", "millisecond", or "milliseconds".
// Each component may be separated by any number of spaces, or none.
// The expression is case-insensitive.
private static readonly Regex DurationRegex = new Regex(#"
((?<Days>\d{1,10})(d|dy|dys|day|days)(\b|(?=[^a-z])))?\s*
((?<Hours>\d{1,10})(h|hr|hrs|hour|hours)(\b|(?=[^a-z])))?\s*
((?<Minutes>\d{1,10})(m|min|minute|minutes)(\b|(?=[^a-z])))?\s*
((?<Seconds>\d{1,10})(s|sec|second|seconds)(\b|(?=[^a-z])))?\s*
((?<Milliseconds>\d{1,10})(ms|msec|millisec|millisecond|milliseconds)(\b|(?=[^a-z])))?",
RegexOptions.IgnoreCase | RegexOptions.IgnorePatternWhitespace);
private static int ParseInt32ZeroIfNullOrEmpty(string input)
{
return string.IsNullOrEmpty(input) ? 0 : int.Parse(input);
}
public static TimeSpan ParseDuration(string input)
{
var match = DurationRegex.Match(input);
return new TimeSpan(
ParseInt32ZeroIfNullOrEmpty(match.Groups["Days"].Value),
ParseInt32ZeroIfNullOrEmpty(match.Groups["Hours"].Value),
ParseInt32ZeroIfNullOrEmpty(match.Groups["Minutes"].Value),
ParseInt32ZeroIfNullOrEmpty(match.Groups["Seconds"].Value),
ParseInt32ZeroIfNullOrEmpty(match.Groups["Milliseconds"].Value));
}

update:
Don't vote for this. I'm leaving it simply because it's an alternative approach. Instead look at sa_ddam213 and Dr. Wily's Apprentice's answers.
Should I separate the suffix, in this case "d", out of the string
first, then try and match it in the enum using a switch statement?
Yes.
For a fully working example:
private void button1_Click( object sender, EventArgs e ) {
String value = "30d";
Duration d = (Duration)Enum.Parse(typeof(Duration), value.Substring(value.Length - 1, 1).ToUpper());
DateTime result = d.From(new DateTime(), value);
MessageBox.Show(result.ToString());
}
enum Duration { D, W, M, Y };
static class DurationExtensions {
public static DateTime From( this Duration duration, DateTime dateTime, Int32 period ) {
switch (duration)
{
case Duration.D: return dateTime.AddDays(period);
case Duration.W: return dateTime.AddDays((period*7));
case Duration.M: return dateTime.AddMonths(period);
case Duration.Y: return dateTime.AddYears(period);
default: throw new ArgumentOutOfRangeException("duration");
}
}
public static DateTime From( this Duration duration, DateTime dateTime, String fullValue ) {
Int32 period = Convert.ToInt32(fullValue.ToUpper().Replace(duration.ToString(), String.Empty));
return From(duration, dateTime, period);
}
}

I really don't see how using an enum helps here.
Here's how I might approach it.
string s = "30d";
int typeIndex = s.IndexOfAny(new char[] { 'd', 'w', 'm' });
if (typeIndex > 0)
{
int value = int.Parse(s.Substring(0, typeIndex));
switch (s[typeIndex])
{
case 'd':
result = DateTime.Now.AddDays(value);
break;
case 'w':
result = DateTime.Now.AddDays(value * 7);
break;
case 'm':
result = DateTime.Now.AddMonths(value);
break;
}
}
Depending on the reliability of your input data, you might need to use int.TryParse() instead of int.Parse(). Otherwise, this should be all you need.
Note: I've also written a sscanf() replacement for .NET that would handle this quite easily. You can see the code for that in the article A sscanf() Replacement for .NET.

Try the following code, assuming that values like "30d" are in a string 'val'.
DateTime ConvertValue(string val) {
if (val.Length > 0) {
int prefix = Convert.ToInt32(val.Length.Remove(val.Length-1));
switch (val[val.Length-1]) {
case 'd': return DateTime.Now.AddDays(prefix);
case 'm': return DateTime.Now.AddMonths(prefix);
// etc.
}
throw new ArgumentException("string in unexpected format.");
}

Example of a console application example/tutorial:
enum DurationType
{
[DisplayName("m")]
Min = 1,
[DisplayName("h")]
Hours = 1 * 60,
[DisplayName("d")]
Days = 1 * 60 * 24
}
internal class Program
{
private static void Main(string[] args)
{
string input1 = "10h";
string input2 = "1d10h3m";
var x = GetOffsetFromDate(DateTime.Now, input1);
var y = GetOffsetFromDate(DateTime.Now, input2);
}
private static Dictionary<string, DurationType> suffixDictionary
{
get
{
return Enum
.GetValues(typeof (DurationType))
.Cast<DurationType>()
.ToDictionary(duration => duration.GetDisplayName(), duration => duration);
}
}
public static DateTime GetOffsetFromDate(DateTime date, string input)
{
MatchCollection matches = Regex.Matches(input, #"(\d+)([a-zA-Z]+)");
foreach (Match match in matches)
{
int numberPart = Int32.Parse(match.Groups[1].Value);
string suffix = match.Groups[2].Value;
date = date.AddMinutes((int)suffixDictionary[suffix]);
}
return date;
}
}
[AttributeUsage(AttributeTargets.Field)]
public class DisplayNameAttribute : Attribute
{
public DisplayNameAttribute(String name)
{
this.name = name;
}
protected String name;
public String Name { get { return this.name; } }
}
public static class ExtensionClass
{
public static string GetDisplayName<TValue>(this TValue value) where TValue : struct, IConvertible
{
FieldInfo fi = typeof(TValue).GetField(value.ToString());
DisplayNameAttribute attribute = (DisplayNameAttribute)fi.GetCustomAttributes(typeof(DisplayNameAttribute), false).FirstOrDefault();
if (attribute != null)
return attribute.Name;
return value.ToString();
}
}
Uses an attribute to define your suffix, uses the enum value to define your offset.
Requires:
using System;
using System.Collections.Generic;
using System.Linq;
using System.Reflection;
using System.Text.RegularExpressions;
It may be considered a hack to use the enum integer value but this example will still let you parse out all the Enums (for any other use like switch case) with little tweaks.

Enums can't be backed with non-numeric types, so string-based enums are out. It's possible you may be overthinking it. Without knowing any more about the problem, the most straightforward solution seems to be splitting off the last character, converting the rest to an int, and then handling each final char as a separate case.

I'd suggest using regexp to strip the number first and than execute Enum.Parse Method to evaluate the value of the enum. Than you can use a switch (see Corylulu's answer) to get the right offset, based on the parsed number and enum value.

Trim last character from a string

I have a string say
"Hello! world!"
I want to do a trim or a remove to take out the ! off world but not off Hello.

"Hello! world!".TrimEnd('!');
read more
EDIT:
What I've noticed in this type of questions that quite everyone suggest to remove the last char of given string. But this does not fulfill the definition of Trim method.
Trim - Removes all occurrences of
white space characters from the
beginning and end of this instance.
MSDN-Trim
Under this definition removing only last character from string is bad solution.
So if we want to "Trim last character from string" we should do something like this
Example as extension method:
public static class MyExtensions
{
public static string TrimLastCharacter(this String str)
{
if(String.IsNullOrEmpty(str)){
return str;
} else {
return str.TrimEnd(str[str.Length - 1]);
}
}
}
Note if you want to remove all characters of the same value i.e(!!!!)the method above removes all existences of '!' from the end of the string,
but if you want to remove only the last character you should use this :
else { return str.Remove(str.Length - 1); }

String withoutLast = yourString.Substring(0,(yourString.Length - 1));

if (yourString.Length > 1)
withoutLast = yourString.Substring(0, yourString.Length - 1);
or
if (yourString.Length > 1)
withoutLast = yourString.TrimEnd().Substring(0, yourString.Length - 1);
...in case you want to remove a non-whitespace character from the end.

The another example of trimming last character from a string:
string outputText = inputText.Remove(inputText.Length - 1, 1);
You can put it into an extension method and prevent it from null string, etc.

Try this:
return( (str).Remove(str.Length-1) );

In .NET 5 / C# 8:
You can write the code marked as the answer as:
public static class StringExtensions
{
public static string TrimLastCharacters(this string str) => string.IsNullOrEmpty(str) ? str : str.TrimEnd(str[^1]);
}
However, as mentioned in the answer, this removes all occurrences of that last character. If you only want to remove the last character you should instead do:
public static string RemoveLastCharacter(this string str) => string.IsNullOrEmpty(str) ? str : str[..^1];
A quick explanation for the new stuff in C# 8:
The ^ is called the "index from end operator". The .. is called the "range operator". ^1 is a shortcut for arr.length - 1. You can get all items after the first character of an array with arr[1..] or all items before the last with arr[..^1]. These are just a few quick examples. For more information, see https://learn.microsoft.com/en-us/dotnet/csharp/whats-new/csharp-8, "Indices and ranges" section.

string s1 = "Hello! world!";
string s2 = s1.Trim('!');

string helloOriginal = "Hello! World!";
string newString = helloOriginal.Substring(0,helloOriginal.LastIndexOf('!'));

string s1 = "Hello! world!"
string s2 = s1.Substring(0, s1.Length - 1);
Console.WriteLine(s1);
Console.WriteLine(s2);

Very easy and simple:
str = str.Remove( str.Length - 1 );

you could also use this:
public static class Extensions
{
public static string RemovePrefix(this string o, string prefix)
{
if (prefix == null) return o;
return !o.StartsWith(prefix) ? o : o.Remove(0, prefix.Length);
}
public static string RemoveSuffix(this string o, string suffix)
{
if(suffix == null) return o;
return !o.EndsWith(suffix) ? o : o.Remove(o.Length - suffix.Length, suffix.Length);
}
}

An example Extension class to simplify this: -
internal static class String
{
public static string TrimEndsCharacter(this string target, char character) => target?.TrimLeadingCharacter(character).TrimTrailingCharacter(character);
public static string TrimLeadingCharacter(this string target, char character) => Match(target?.Substring(0, 1), character) ? target.Remove(0,1) : target;
public static string TrimTrailingCharacter(this string target, char character) => Match(target?.Substring(target.Length - 1, 1), character) ? target.Substring(0, target.Length - 1) : target;
private static bool Match(string value, char character) => !string.IsNullOrEmpty(value) && value[0] == character;
}
Usage
"!Something!".TrimLeadingCharacter('X'); // Result '!Something!' (No Change)
"!Something!".TrimTrailingCharacter('S'); // Result '!Something!' (No Change)
"!Something!".TrimEndsCharacter('g'); // Result '!Something!' (No Change)
"!Something!".TrimLeadingCharacter('!'); // Result 'Something!' (1st Character removed)
"!Something!".TrimTrailingCharacter('!'); // Result '!Something' (Last Character removed)
"!Something!".TrimEndsCharacter('!'); // Result 'Something' (End Characters removed)
"!!Something!!".TrimLeadingCharacter('!'); // Result '!Something!!' (Only 1st instance removed)
"!!Something!!".TrimTrailingCharacter('!'); // Result '!!Something!' (Only Last instance removed)
"!!Something!!".TrimEndsCharacter('!'); // Result '!Something!' (Only End instances removed)

Slightly modified version of #Damian Leszczyński - Vash that will make sure that only a specific character will be removed.
public static class StringExtensions
{
public static string TrimLastCharacter(this string str, char character)
{
if (string.IsNullOrEmpty(str) || str[str.Length - 1] != character)
{
return str;
}
return str.Substring(0, str.Length - 1);
}
}

I took the path of writing an extension using the TrimEnd just because I was already using it inline and was happy with it...
i.e.:
static class Extensions
{
public static string RemoveLastChars(this String text, string suffix)
{
char[] trailingChars = suffix.ToCharArray();
if (suffix == null) return text;
return text.TrimEnd(trailingChars);
}
}
Make sure you include the namespace in your classes using the static class ;P and usage is:
string _ManagedLocationsOLAP = string.Empty;
_ManagedLocationsOLAP = _validManagedLocationIDs.RemoveLastChars(",");

If you want to remove the '!' character from a specific expression("world" in your case), then you can use this regular expression
string input = "Hello! world!";
string output = Regex.Replace(input, "(world)!", "$1", RegexOptions.Multiline | RegexOptions.Singleline);
// result: "Hello! world"
the $1 special character contains all the matching "world" expressions, and it is used to replace the original "world!" expression