Develop Reference

How do i insert spaces between every letter in a string in C#?

I would like to know how I can insert spaces between every letter in a certain string. E.g. test123 turns into t e s t 1 2 3, Does anyone know?

As said in comments, simply do that:
var result = string.Join(" ", "test123".ToCharArray());
or, to avoid an unnecessary copy string made by ToCharArray:
var result = string.Join<char>(" ", "test123");

Start at the end of the string and keep adding a white space as you work your way to the beginning. By working backwards, you don't need to worry about changing lengths or indices. https://dotnetfiddle.net/fC0yec
int i = str.Length-1;
StringBuilder sb = new StringBuilder(str);
while(i > 0){
sb.Insert(i, " ");
i--;
}
string spacedOutStr = sb.ToString();

How to fix Join(" ") doesnt add a space to the concatenated string

When i try to Join() an array with words and try to add a space to it,
The space seems to be left out, any idea why?
A little background info, when i try to reverse a string of words given to me so that
"hi my name is" should become "is name my hi"
public static string ReverseWords(string text)
{
string[] words = text.Split(' ');
string s = "";
for (int i = words.Length - 1; i >= 0; i--)
{
s+= string.Join(" ", words [i]);
}
return s;
}
The expected outcome would have been: "world! hello"
But it was: "world!hello"
As you can see I'm missing the space between world! and hello.
Any ideas?

You're calling Join with a single word at a time, using the overload accepting a parameter array. Joining a single item will always just return that item - there's nothing else to join it with.
Instead of that, just call it with all the words, in reverse order:
public static string ReverseWords(string text)
{
string[] words = text.Split(' ');
return string.Join(" ", words.Reverse());
}

Join combines the elements of the array with the specified separator, but you are adding each element separately. So no space is added.
string.Join(" ", words.Reverse());

string.Join() is designed to work on a list of strings, placing the separator char between each. You're only giving it one at a time, hence no separator. Try this:
public static string ReverseWords(string text)
{
string[] words = text.Split(' ');
return string.Join(" ", words.Reverse());
}

sorry that it took me a while guys, im still a beginner.
But the .Reverse() function wasnt it because it would turn every char in the word backwards, which wasnt my objective.
The trick was as following:
public static string ReverseWords(string text)
{
string[] words = text.Split(' ');
string s = words[words.Length - 1];
for (int i = words.Length - 2; i >= 0; i--)
{
s+= " " + words[i];
}
return s;
}
}
really alot of thanks with guiding.
#igor you where right, i kept trying to do this exercise in an online environment when i copied it to VS i could discover what was wrong by slowly debugging.

C# how to pick out certain part in a string

I have a string in a masked TextBox that looks like this:
123.456.789.abc.def.ghi
"---.---.---.---.---.---" (masked TextBox format when empty, cannot use underscore X( )
Please ignore the value of the characters (they can be duplicated, and not unique as above). How can I pick out part of the string, say "789"? String.Remove() does not work, as it removes everything after the index.

You could use Split in order to separate your values if the . is always contained in your string.
string input = "123.456.789.abc.def";
string[] mySplitString = input.Split('.');
for (int i = 0; i < mySplitString.Length; i++)
{
// Do you search part here
}

Do you mean you want to obtain that part of the string? If so, you could use string.Split
string s = "123.456.789.abc.def.ghi";
var splitString = s.Split('.');
// splitString[2] will return "789"

You could simply use String.Split (if the string is actually what you have shown)
string str = "123.456.789.abc.def.ghi";
string[] parts = str.Split('.');
string third = parts.ElementAtOrDefault(2); // zero based index
if(third != null)
Console.Write(third);
I've just used Enumerable.ElementAtOrDefault because it returns null instead of an exception if there's no such index in the collection(It falls back to parts[2]).

Finding a string:
string str="123.456.789.abc.def.ghi";
int i = str.IndexOf("789");
string subStr = str.Substring(i,3);
Replacing the substring:
str = str.Replace("789","").Replace("..",".");
Regex:
str = Regex.Replace(str,"789","");
The regex can give you a lot of flexibility finding things with minimum code, the drawback is it may be difficult to write them

If you know the index of where your substring begins and the length that it will be, you can use String.Substring(). This will give you the substring:
String myString = "123.456.789";
// looking for "789", which starts at index 8 and is length 3
String smallString = myString.Substring(8, 3);
If you are trying to remove a specific part of the string, use String.Replace():
String myString = "123.456.789";
String smallString = myString.Replace("789", "");

var newstr = new String(str.where(c => "789")).tostring();..i guess this would work or you can use sumthng like this

Try using Replace.
String.Replace("789", "")

Go to each white space in a string. C#

Is it possible to pass over a string, finding the white spaces?
For example a data set of:
string myString = "aa bbb cccc dd";
How could I loop through and detect each white space, and manipulate that space?
I need to do this in the most effecient way possible.
Thanks.
UPDATE:
I need to manipulate the space by increasing the white space from an integer value. So for instance increase the space to have 3 white spaces instead of one. I'd like to make it go through each white space in one loop, any method of doing this already in .NET? By white space I mean a ' '.

You can use the Regex.Replace method. This will replace any group of white space character with a dash:
myString = Regex.Replace(myString, "(\s+)", m => "-");
Update:
This will find groups of space characters and replace with the tripple amount of spaces:
myString = Regex.Replace(
myString,
"( +)",
m => new String(' ', m.Groups[1].Value.Length * 3)
);
However, that's a bit too simple to make use of regular expressions. You can do the same with a regular replace:
myString = myString.Replace(" ", " ");
This will replace each space intead of replace groups of spaces, but the regular replace is much simpler than Regex.Replace, so it should still be at least as fast, and the code is simpler.

If you want to replace all whitespace in one swoop, you can do:
// changes all strings to dashes
myString.Replace(' ', '-');
If you want to go case by case (that is, not just a mass replace), you can loop through IndexOf():
int pos = myString.IndexOf(' ');
while (pos >= 0)
{
// do whatever you want with myString # pos
// find next
pos = myString.IndexOf(' ', pos + 1);
}
UPDATE
As per your update, you could replace single spaces with the number of spaces specified by a variable (such as numSpaces) as follows:
myString.Replace(" ", new String(' ', numSpaces));

If you just want to replace all spaces with some other character:
myString = myString.Replace(' ', 'x');
If you need the possibility of doing something different to each:
foreach(char c in myString)
{
if (c == ' ')
{
// do something
}
}
Edit:
Per your comment clarifying your question:
To change each space to three spaces, you can do this:
myString = myString.Replace(" ", " ");
However note that this doesn't take into account instances where your input string already has two or more spaces. If that is a possibility you will want to use a regex.

Depending on what you're tring to do:
for(int k = 0; k < myString.Length; k++)
{
if(myString[k].IsWhiteSpace())
{
// do something with it
}
}
The above is a single pass through the string, so it's O(n). You can't really get more efficient that that.
However, if you want to manipulate the original string your best bet is to Use a StringBuilder to process the changes:
StringBuilder sb = new StringBuilder(myString);
for(int k = 0; k < myString.Length; k++)
{
if(myString[k].IsWhiteSpace())
{
// do something with sb
}
}
Finally, don't forget about Regular Expressions. It may not always be the most efficient method in terms of code run-time complexity but as far as efficiency of coding it may be a good trade-off.
For instance, here's a way to match all white spaces:
var rex = new System.Text.RegularExpressions.Regex("[^\\s](\\s+)[^\\s]");
var m = rex.Match(myString);
while(m.Success)
{
// process the match here..
m.NextMatch();
}
And here's a way to replace all white spaces with an arbitrary string:
var rex = new System.Text.RegularExpressions.Regex("\\s+");
String replacement = "[white_space]";
// replaces all occurrences of white space with the string [white_space]
String result = rex.Replace(myString, replacement);

Use string.Replace().
string newString = myString.Replace(" ", " ");

LINQ query below returns a set of anonymous type items with two properties - "sybmol" represents a white space character, and "index" - index in the input sequence. After that you have all whitespace characters and a position in the input sequence, now you can do what you want with this.
string myString = "aa bbb cccc dd";
var res = myString.Select((c, i) => new { symbol = c, index = i })
.Where(c => Char.IsWhiteSpace(c.symbol));
EDIT: For educational purposes below is implementation you are looking for, but obviously in real system use built in string constructor and String.Replace() as shown in other answers
string myString = "aa bbb cccc dd";
var result = this.GetCharacters(myString, 5);
string output = new string(result.ToArray());
public IEnumerable<char> GetCharacters(string input, int coeff)
{
foreach (char c in input)
{
if (Char.IsWhiteSpace(c))
{
int counter = coeff;
while (counter-- > 0)
{
yield return c;
}
}
else
{
yield return c;
}
}
}

var result = new StringBuilder();
foreach(Char c in myString)
{
if (Char.IsWhiteSpace(c))
{
// you can do what you wish here. strings are immutable, so you can only make a copy with the results you want... hence the "result" var.
result.Append('_'); // for example, replace space with _
}
else result.Append(c);
}
myString = result.ToString();

If you want to replace the white space with, e.g. '_', you can using String.Replace.
Example:
string myString = "aa bbb cccc dd";
string newString = myString.Replace(" ", "_"); // gives aa_bbb_cccc_dd

In case you want to left/right justify your string
int N=10;
string newstring = String.Join(
"",
myString.Split(' ').Select(s=>s.PadRight(N-s.Length)));

How to remove words based on a word count

Here is what I'm trying to accomplish. I have an object coming back from
the database with a string description. This description can be up to 1000
characters long, but we only want to display a short view of this. So I coded
up the following, but I'm having trouble in actually removing the number of
words after the regular expression finds the total count of words. Does anyone
have good way of dispalying the words which are less than the Regex.Matches?
Thanks!
if (!string.IsNullOrEmpty(myObject.Description))
{
string original = myObject.Description;
MatchCollection wordColl = Regex.Matches(original, #"[\S]+");
if (wordColl.Count < 70) // 70 words?
{
uxDescriptionDisplay.Text =
string.Format("<p>{0}</p>", myObject.Description);
}
else
{
string shortendText = original.Remove(200); // 200 characters?
uxDescriptionDisplay.Text =
string.Format("<p>{0}</p>", shortendText);
}
}
EDIT:
So this is what I got working on my own:
else
{
int count = 0;
StringBuilder builder = new StringBuilder();
string[] workingText = original.Split(' ');
foreach (string word in workingText)
{
if (count < 70)
{
builder.AppendFormat("{0} ", word);
}
count++;
}
string shortendText = builder.ToString();
}
It's not pretty, but it worked. I would call it a pretty naive way of doing this. Thanks for all of the suggestions!

I would opt to go by a strict character count rather than a word count because you might happen to have a lot of long words.
I might do something like (pseudocode)
if text.Length > someLimit
find first whitespace after someLimit (or perhaps last whitespace immediately before)
display substring of text
else
display text
Possible code implementation:
string TruncateText(string input, int characterLimit)
{
if (input.Length > characterLimit)
{
// find last whitespace immediately before limit
int whitespacePosition = input.Substring(0, characterLimit).LastIndexOf(" ");
// or find first whitespace after limit (what is spec?)
// int whitespacePosition = input.IndexOf(" ", characterLimit);
if (whitespacePosition > -1)
return input.Substring(0, whitespacePosition);
}
return input;
}

One method, if you're using at least C#3.0, would be a LINQ like the following. This is provided you're going strictly by word count, not character count.
if (wordColl.Count > 70)
{
foreach (var subWord in wordColl.Cast<Match>().Select(r => r.Value).Take(70))
{
//Build string here out of subWord
}
}
I did a test using a simple Console.WriteLine with your Regex and your question body (which is over 70 words, it turns out).

You can use Regex Capture Groups to hold the match and access it later.
For your application, I'd recommend instead simply splitting the string by spaces and returning the first n elements of the array:
if (!string.IsNullOrEmpty(myObject.Description))
{
string original = myObject.Description;
string[] words = original.Split(' ');
if (words.Length < 70)
{
uxDescriptionDisplay.Text =
string.Format("<p>{0}</p>", original);
}
else
{
string shortDesc = string.Empty;
for(int i = 0; i < 70; i++) shortDesc += words[i] + " ";
uxDescriptionDisplay.Text =
string.Format("<p>{0}</p>", shortDesc.Trim());
}
}

Are you wanting to remove 200 characters or start truncating at the 200th character? When you call original.Remove(200) you are indexing the start of the truncation at the 200th character. This is how you use Remove() for a certain number of characters to remove:
string shortendText = original.Remove(0,200);
This starts at the first character and removes 200 starting with that one. Which I imagine that's not what you're trying to do since you're shortening a description. That's merely the correct way to use Remove().
Instead of using Regex matchcollections why not just split the string? It's a lot easier and straight forward. You can set the delimiter to a space character and split that way. Not sure if that completely fixes your need but it just might. I'm not sure what your data looks like in the description. But you split this way:
String[] wordArray = original.Split(' ');
From there you can determine the word count with wordArray's Length property value.

If I was you I would go by characters as you may have many one letter words or many long words in your text.
Go through until characters <= your limit, then either find the next space and then add these characters to a new string (possibly using the SubString method) or take these characters and add a few full stops, then make a new string The later could be unproffessional I suppose.