Develop Reference

Alternatively upper- and lowercase words in a string

I use Visual Studio 2010 ver.
I have array strings [] = { "eat and go"};
I display it with foreach
I wanna convert strings like this : EAT and GO
Here my code:
Console.Write( myString.First().ToString().ToUpper() + String.Join("",myString].Skip(1)).ToLower()+ "\n");
But the output is : Eat and go . :D lol
Could you help me? I would appreciate it. Thanks

While .ToUpper() will convert a string to its upper case equivalent, calling .First() on a string object actually returns the first element of the string (since it's effectively a char[] under the hood). First() is actually exposed as a LINQ extension method and works on any collection type.
As with many string handling functions, there are a number of ways to handle it, and this is my approach. Obviously you'll need to validate value to ensure it's being given a long enough string.
using System.Text;
public string CapitalizeFirstAndLast(string value)
{
string[] words = value.Split(' '); // break into individual words
StringBuilder result = new StringBuilder();
// Add the first word capitalized
result.Append(words[0].ToUpper());
// Add everything else
for (int i = 1; i < words.Length - 1; i++)
result.Append(words[i]);
// Add the last word capitalized
result.Append(words[words.Length - 1].ToUpper());
return result.ToString();
}

If it's always gonna be a 3 words string, the you can simply do it like this:
string[] mystring = {"eat and go", "fast and slow"};
foreach (var s in mystring)
{
string[] toUpperLower = s.Split(' ');
Console.Write(toUpperLower.First().ToUpper() + " " + toUpperLower[1].ToLower() +" " + toUpperLower.Last().ToUpper());
}

If you want to continuously alternate, you can do the following:
private static string alternateCase( string phrase )
{
String[] words = phrase.split(" ");
StringBuilder builder = new StringBuilder();
//create a flag that keeps track of the case change
book upperToggle = true;
//loops through the words
for(into i = 0; i < words.length; i++)
{
if(upperToggle)
//converts to upper if flag is true
words[i] = words[i].ToUpper();
else
//converts to lower if flag is false
words[i] = words[i].ToLower();
upperToggle = !upperToggle;
//adds the words to the string builder
builder.append(words[i]);
}
//returns the new string
return builder.ToString();
}

Quickie using ScriptCS:
scriptcs (ctrl-c to exit)
> var input = "Eat and go";
> var words = input.Split(' ');
> var result = string.Join(" ", words.Select((s, i) => i % 2 == 0 ? s.ToUpperInvariant() : s.ToLowerInvariant()));
> result
"EAT and GO"

how to get the substring

I have a string something like this 1234ABCD-1A-AB I have separator in string[] separator , I am looping till the length of string. I want to get the substring. inside the loop i am writing below code
string tempVar = test.Substring(0, test.IndexOf("'" + separator+ "'"));
I tried like this as well
string tempVar = String.Join(",", test.Split(',').Select(s => s.Substring(0, s.IndexOf("'" + separator+ "'"))));
by using this I am getting error Index should not be less that 0, Loop will run only 2 times because i am loop based on separator, and I have 2 separator in my string.
let me explain:
I have a loop for separator which will execute only 2 time because I'll 2 separator one is 9th position and other one is 14th positing, inside that loop I am splitting the string based on separator
string[] test1 = test.Split("'" + separator+ "'");
in my next step I am passing one string value for next process like this
string temp = test1[i].ToString();
with this i am getting only 2 string that is 1234ABCD and 1A I want to get the 3rd value as well inside the loop. So I thought of taking the substring than using split.
output should be:
first time: 1234ABCD
second time: 1A
third time: AB

You can use Split with your separator '-' and then access the returned string[].
string[] parts = test.Split('-');
string firstPart = parts[0];
string secondPart = parts.ElementAtOrDefault(1);
string thirdPart = parts.ElementAtOrDefault(2);
Demo

Use the split function:
string s = "1234ABCD-1A-AB";
string[] parts = s.Split('-');
then:
s[0] == "1234ABCD"
s[1] == "1A"
s[2] == "AB"
Based on the now updated requirements, try the following:
string input = "1234ABCD-1A-AB";
char separator = '-';
string[] parts = input.Split(separator);
// if you do not need to know the item index:
foreach (string item in parts)
{
// do something here with 'item'
}
// if you need to know the item index:
for (int i = 0; i < parts.Length; i++)
{
// do something here with 'item[i]', where i is
// the index (so 1, 2, or 3 in your case).
}

string[] items = str.Split(new char[] { '-' });

you can use String.Split():
string str = "1234ABCD-1A-AB";
string[] splitted = str.Split('-');
/* foreach (string item in splitted)
{
Console.WriteLine(item);
}*/
and you can set it as:
string firstPart = splitted.FirstOrDefault();
string secondPart = splitted.ElementAtOrDefault(1);
string thirdPart = splitted.ElementAtOrDefault(2);

You can use String.Split method
Returns a string array that contains the substrings in this instance
that are delimited by elements of a specified string or Unicode
character array.
string s = "1234ABCD-1A-AB";
string[] items = s.Split('-');
for(int i = 0; i < items.Length; i++)
Console.WriteLine("Item number {0} is: {1}", i, items[i]);
Output will be;
Item number 0 is: 1234ABCD
Item number 1 is: 1A
Item number 2 is: AB
Here is a DEMO.

I was only missing the index
string tempVar = test.Substring(0, test.IndexOf(separator[0].ToString()));

Very simple via String.Split():
string t = "1234ABCD-1A-AB";
string[] tempVar = t.Split('-');
foreach(string s in tempVar)
{
Console.WriteLine(s);
}
Console.Read();
Prints:
1234ABCD
1A
AB

C# fix sentence

I need to take a sentence in that is all on one line with no spaces and each new word has a captial letter EX. "StopAndSmellTheRoses" and then convert it to "Stop and smell the roses" This is my function that I have but I keep getting an argument out of range error on the insert method. Thanks for any help in advance.
private void FixSentence()
{
// String to hold our sentence in trim at same time
string sentence = txtSentence.Text.Trim();
// loop through the string
for (int i = 0; i < sentence.Length; i++)
{
if (char.IsUpper(sentence, i) & sentence[i] != 0)
{
// Change to lowercase
char.ToLower(sentence[i]);
// Insert space behind the character
// This is where I get my error
sentence = sentence.Insert(i-1, " ");
}
}
// Show our Fixed Sentence
lblFixed.Text = "";
lblFixed.Text = "Fixed: " + sentence;
}

The best way to build up a String in this manner is to use a StringBuilder instance.
var sentence = txtSentence.Text.Trim();
var builder = new StringBuilder();
foreach (var cur in sentence) {
if (Char.IsUpper(cur) && builder.Length != 0) {
builder.Append(' ');
}
builder.Append(cur);
}
// Show our Fixed Sentence
lblFixed.Text = "";
lblFixed.Text = "Fixed: " + builder.ToString();
Using the Insert method creates a new string instance every time resulting in a lot of needlessly allocated values. The StringBuilder though won't actually allocate a String until you call the ToString method.

You can't modify the sentence variable in the loop that is going through it.
Instead, you need to have a second string variable that you append all of the found words.

Here is the answer
var finalstr = Regex.Replace(
"StopAndSmellTheRoses",
"(?<=[a-z])(?<x>[A-Z])|(?<=.)(?<x>[A-Z])(?=[a-z])|(?<=[^0-9])(?<x>[0-9])(?=.)",
me => " " + me.Value.ToLower()
);
will output
Stop and smell the roses

Another version:
public static class StringExtensions
{
public static string FixSentence(this string instance)
{
char[] capitals = Enumerable.Range(65, 26).Select(x => (char)x).ToArray();
string[] words = instance.Split(capitals);
string result = string.Join(' ', words);
return char.ToUpper(result[0]) + result.Substring(1).ToLower();
}
}

Getting parts of a string and combine them in C#?

I have a string like this: C:\Projects\test\whatever\files\media\10\00\00\80\test.jpg
Now, what I want to do is to dynamically combine the last 4 numbers, in this case its 10000080 as result. My idea was ti split this and combine them in some way, is there an easier way? I cant rely on the array index, because the path can be longer or shorter as well.
Is there a nice way to do that?
Thanks :)

A compact way using string.Join and Regex.Split.
string text = #"C:\Projects\test\whatever\files\media\10\00\00\80\test.jpg";
string newString = string.Join(null, Regex.Split(text, #"[^\d]")); //10000080

Use String.Split
String toSplit = "C:\Projects\test\whatever\files\media\10\00\00\80\test.jpg";
String[] parts = toSplit.Split(new String[] { #"\" });
String result = String.Empty;
for (int i = 5, i > 1; i--)
{
result += parts[parts.Length - i];
}
// Gives the result 10000080

You can rely on array index if the last part always is the filename.
since the last part is always
array_name[array_name.length - 1]
the 4 parts before that can be found by
array_name[array_name.length - 2]
array_name[array_name.length - 3]
etc

If you always want to combine the last four numbers, split the string (use \ as the separator), start counting from the last part and take 4 numbers, or the 4 almost last parts.
If you want to take all the digits, just scan the string from start to finish and copy just the digits to a new string.

string input = "C:\Projects\test\whatever\files\media\10\00\00\80\test.jpg";
string[] parts = toSplit.Split(new char[] {'\\'});
IEnumerable<string> reversed = parts.Reverse();
IEnumerable<string> selected = reversed.Skip(1).Take(4).Reverse();
string result = string.Concat(selected);
The idea is to extract the parts, reverse them to keep only the last 4 (excluding the file name) and re reversing to rollback to the initial order, then concat.

Using LINQ:
string path = #"C:\Projects\test\whatever\files\media\10\00\00\80\test.jpg";
var parts = Path.GetDirectoryName(path).Split('\\');
string numbersPart = parts.Skip(parts.Count() - 4)
.Aggregate((acc, next) => acc + next);
Result: "10000080"

var r = new Regex(#"[^\d+]");
var match = r
.Split(#"C:\Projects\test\whatever\files\media\10\00\00\80\test.jpg")
.Aggregate((i, j) => i + j);
return match.ToString();

to find the number you can use regex:
(([0-9]{2})\\){4}
use concat all inner Group ([0-9]{2}) to get your searched number.
This will always find your searched number in any position in the given string.
Sample Code:
static class TestClass {
static void Main(string[] args) {
string[] tests = { #"C:\Projects\test\whatever\files\media\10\00\00\80\test.jpg",
#"C:\Projects\test\whatever\files\media\10\00\00\80\some\foldertest.jpg",
#"C:\10\00\00\80\test.jpg",
#"C:\10\00\00\80\test.jpg"};
foreach (string test in tests) {
int number = ExtractNumber(test);
Console.WriteLine(number);
}
Console.ReadLine();
}
static int ExtractNumber(string path) {
Match match = Regex.Match(path, #"(([0-9]{2})\\){4}");
if (!match.Success) {
throw new Exception("The string does not contain the defined Number");
}
//get second group that is where the number is
Group #group = match.Groups[2];
//now concat all captures
StringBuilder builder = new StringBuilder();
foreach (var capture in #group.Captures) {
builder.Append(capture);
}
//pares it as string and off we go!
return int.Parse(builder.ToString());
}
}

Using String Split

I have a text
Category2,"Something with ,comma"
when I split this by ',' it should give me two string
Category2
"Something with ,comma"
but in actual it split string from every comma.
how can I achieve my expected result.
Thanx

Just call variable.Split(new char[] { ',' }, 2). Complete documentation in MSDN.

There are a number of things that you could be wanting to do here so I will address a few:
Split on the first comma
String text = text.Split(new char[] { ',' }, 2);
Split on every comma
String text = text.Split(new char[] {','});
Split on a comma not in "
var result = Regex.Split(samplestring, ",(?=(?:[^']*'[^']*')*[^']*$)");
Last one taken from C# Regex Split

Specify the maximum number of strings you want in the array:
string[] parts = text.Split(new char[] { ',' }, 2);

String.Split works at the simplest, fastest level - so it splits the text on all of the delimiters you pass into it, and it has no concept of special rules like double-quotes.
If you need a CSV parser which understands double-quotes, then you can write your own or there are some excellent open source parsers available - e.g. http://www.codeproject.com/KB/database/CsvReader.aspx - this is one I've used in several projects and recommend.

Try this:
public static class StringExtensions
{
public static IEnumerable<string> SplitToSubstrings(this string str)
{
int startIndex = 0;
bool isInQuotes = false;
for (int index = 0; index < str.Length; index++ )
{
if (str[index] == '\"')
isInQuotes = !isInQuotes;
bool isStartOfNewSubstring = (!isInQuotes && str[index] == ',');
if (isStartOfNewSubstring)
{
yield return str.Substring(startIndex, index - startIndex).Trim();
startIndex = index + 1;
}
}
yield return str.Substring(startIndex).Trim();
}
}
Usage is pretty simple:
foreach(var str in text.SplitToSubstrings())
Console.WriteLine(str);