How to Create Char Array of Letters from a String Array? (C#)
For Example, I Have a String: "Nice to Meet You", There Are 13 Letters When We Count Repeating Letters, but I Wanna Create a Char Array of Letters from This...
For example, I have a string:
"Nice to meet you"
, there are 13 letters when we count repeating letters, but I wanna create a char array of letters from this string without repeating letters, I mean for the string above it should create an array like
{'N', 'i', 'c', 'e', 't', 'o', 'y', 'u', 'm'}
I was looking for answers on google for 2 hours, but I found nothing, there were lots of answers about strings and char arrays, but were not answers for my situation. I thought that I can write code by checking every letter in the array by 2 for cycles but this time I got syntax errors, so I decided to ask.
7 Answers
You can do this:
var foo = "Nice to meet you";
var fooArr = s.ToCharArray();
HashSet<char> set = new();
set.UnionWith(fooArr);
//or if you want without whitespaces you could refactor this as below
set.UnionWith(fooArr.Where(c => c != ' '));
UPDATE: You could even make an extension method:
public static IEnumerable<char> ToUniqueCharArray(this string source, char? ignoreChar)
{
var charArray = source.ToCharArray();
HashSet<char> set = new();
set.UnionWith(charArray.Where(c => c != ignoreChar));
return set;
}
And then you can use it as:
var foo = "Nice to meet you";
var uniqueChars = foo.ToUniqueCharArray(ignoreChar: ' ');
// if you want to keep the whitespace
var uniqueChars = foo.ToUniqueCharArray(ignoreChar: null);
this piece of code does the job:
var sentence = "Nice To meet you";
var arr = sentence.ToLower().Where(x => x !=' ' ).ToHashSet();
Console.WriteLine(string.Join(",", arr));
I have added ToLower() if you dont do differences between uppercase and lowercase, if case is sensitive you just put off this extension..
HashSet suppresses all duplicates letters
test: Fiddle
I tried this one and it works too
"Nice to meet you".Replace(" ", "").ToCharArray().Distinct();
A very short solution is to use .Except() on the input string:
string text = "Nice to meet you";
char[] letters = text.Except(" ").ToArray();
Here, .Except():
- translates both the text string and the parameter string (
" ") to char collections - filters out all the chars in the text char collection that are present in the parameter char collection
- returns a collection of distinct chars from the filtered text char collection
Example fiddle here.
Visualizing the process
Let's use the blue banana as an example.
var input = "blue banana";
input.Except(" ")will be translated to:
{ 'b', 'l', 'u', 'e', ' ', 'b', 'a', 'n', 'a', 'n', 'a' }.Except({ ' ' })
- Filtering out all
' 'occurrences in the text char array produces:
{ 'b', 'l', 'u', 'e', 'b', 'a', 'n', 'a', 'n', 'a' }
- The distinct char collection will have all the duplicates of
'b','a'and'n'removed, resulting in:
{ 'b', 'l', 'u', 'e', 'a', 'n' }
ToCharArray method of string is only thing you need.
using System;
public class HelloWorld
{
public static void Main(string[] args)
{
string str = "Nice to meet you";
char[] carr = str.ToCharArray();
for(int i = 0; i < carr.Length; i++)
Console.WriteLine (carr[i]);
}
}
String str = "Nice To meet you";
char[] letters = str.ToLower().Except(" ").ToArray();
A solution just using for-loops (no generics or Linq), with comments explaining things:
// get rid of the spaces
String str = "Nice to meet you".Replace(" ", "");
// a temporary array more than long enough (we will trim it later)
char[] temp = new char[str.Length];
// the index where to insert the next char into "temp". This is also the length of the filled-in part
var idx = 0;
// loop through the source string
for (int i=0; i<str.Length; i++)
{
// get the character at this position (NB "surrogate pairs" will fail here)
var c = str[i];
// did we find it in the following loop?
var found = false;
// loop through the collected characters to see if we already have it
for (int j=0; j<idx; j++)
{
if (temp[j] == c)
{
// yes, we already have it!
found = true;
break;
}
}
if (!found)
{
// we didn't already have it, so add
temp[idx] = c;
idx+=1;
}
}
// "temp" is too long, so create a new array of the correct size
var letters = new char[idx];
Array.Copy(temp, letters, idx);
// now "letters" contains the unique letters
That "surrogate pairs" remark basically means that emojis will fail.
Elena Rostova holds a Master's degree in Public Health Journalism. She covers groundbreaking medical research, holistic wellness trends, mental health awareness, and nutritional science.
