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I need to check if each digit from an integer is even or odd in c# an return even or odd

I'm new to c# language and still learning. I have to write a console application (like example) but the real problem for me is that I don't know how to access each number for the input integer and pass it on the division function (n % 2 ==0) and return even/odd for the given number.
For example:
the user input: 4444
and the console result: even
even
even
even
string inputData = Console.ReadLine(); // the 4 digit number
int number = Convert.ToInt32(inputData);
string emptyStr = String.Empty;
string divided = "even";
string notDivided = "odd";
// here .......????
if (number % 2 == 0)
{
Console.WriteLine(divided);
}
else
{
Console.WriteLine(notDivided);
}

I think this is what you are looking for.
First of all use this
Is there an easy way to turn an int into an array of ints of each digit?
After that just check every individual item in your array
public void main
{
var numbers = NumbersIn(987654321).ToArray();
foreach (int element in numbers)
{
if (element % 2 == 0)
{
Console.Write("even");
}
else
{
Console.Write("uneven");
}
}
}
public Stack<int> NumbersIn(int value)
{
if (value == 0) return new Stack<int>();
var numbers = NumbersIn(value / 10);
numbers.Push(value % 10);
return numbers;
}

https://learn.microsoft.com/en-us/dotnet/api/system.console.readline?view=netcore-3.1 you can use the hyperlink provided to use the method Console.ReadLine method for the conditional output that you are C#-ing.

You can read each key written by user in loop with:
var digit = Console.ReadKey()
Remember to parse char to int properly.
As Mong Zhu noticed, you cannot parse char value with: Int32.Parse('1'). You have to do it with string value.
So full solution is:
var digitStr = Console.ReadKey();
var digit = Int32.Parse(digitStr.KeyChar.ToString());

Import x and y coordinates from .txt file

I need to read coordinates from text file for my project,but the text file is like this
1 37.4393516691 541.2090699418
2 612.1759508571 494.3166877396
3 38.1312338227 353.1484581781
and with more space in front.I have code that i tried but i couldn't make the seperators work.
1 1150.0 1760.0
2 630.0 1660.0
3 40.0 2090.0
The code:
string[] cityPositions = File.ReadAllLines(ofd.FileName);
foreach (string cityP in cityPositions)
{
int startIndexX = cityP.IndexOf(" ", StringComparison.CurrentCultureIgnoreCase) + 3;
int endIndexX = cityP.IndexOf(" ", StringComparison.CurrentCultureIgnoreCase);
int X = int.Parse(cityP.Substring(startIndexX, endIndexX - startIndexX));
int startIndexY = cityP.IndexOf(" ", StringComparison.CurrentCultureIgnoreCase) + 3;
int endIndexY = cityP.IndexOf("", StringComparison.CurrentCultureIgnoreCase);
int Y = int.Parse(cityP.Substring(startIndexY, endIndexY - startIndexY));
create_City(new Point(X, Y));
}

If you want to make use of Regular Expressions, try this:
String expression = #"(\d)([\d\.]*)([\d\.]*)";
Regex r = new Regex(expression);
foreach (String cityPosition in cityPositions)
{
MatchCollection mc = r.Matches(cityPosition);
int index = Convert.ToInt32(mc[0].Value);
decimal coOrdX = Convert.ToDecimal(mc[1].Value);
decimal coOrdY = Convert.ToDecimal(mc[2].Value);
Console.WriteLine(String.Format("{0} {1} {2}", index, coOrdX, coOrdY));
}
This code will produce this output:
1 1150.0 1760.0
2 630.0 1660.0
3 40.0 2090.0
It should disregard the varying amount of space between the values and make it easier to parse the three different values in the file.

First of all your data type doesnt match. You should use double for coordinates, and use Split method, for example:
double X = double.Parse(cityP.Split()[1], CultureInfo.InvariantCulture);
double Y = double.Parse(cityP.Split()[2], CultureInfo.InvariantCulture);
Split function with no parameters given will split by whitespace.
EDIT
It's not clear in the question but, if your lines dont have the same pattern, and have different spaces use Split method like this:
double X = double.Parse(cityP.Split(new[] { ' ' }, StringSplitOptions.RemoveEmptyEntries)[1], CultureInfo.InvariantCulture);

Instead of working with indices, you could Replace multiple whitespaces with a single whitespace, like
RegexOptions options = RegexOptions.None;
Regex regex = new Regex("[ ]{2,}", options);
cityP = regex.Replace(cityP, " ");
then use split to get the coordinates
var x = double.Parse(cityP.Split()[1]);
var y = double.Parse(cityP.Split()[2]);

Using Substring to get digit before a string

I am reading a file in C#. I want to check value from a string. The line consists as following:
15 EMP_L_NAME HAPPENS 5 TIMES.
40 SUP HAPPENS 12 TIMES.
I want to find the number of times which is in the string before the string "TIMES". I have written the following code:
int arrayLength = 0;
int timesindex = line.IndexOf("TIMES");
if (timesindex > 0)
{
//Positon of the digit "5" in the first line
int indexCount = timesindex - 2;
if (int.TryParse(line.Substring(indexCount, 1), out occursCount))
{
arrayLength = occursCount;
}
}
Using the above code, I can find the number of "TIMES" for a single digigt number. But if it is a double digit, it won't work( e.g the second line). I have to develop a logic to find the digit which is separted by a space with "TIMES". How I can do that?

You can do:
Split your string on space and remove empty enteries.
Find Index of "TIMES."
Access element Index - 1
Like:
string str = "15 EMP_L_NAME HAPPENS 5 TIMES. ";
string[] array = str.Split(new[] { ' ' }, StringSplitOptions.RemoveEmptyEntries);
int index = Array.IndexOf(array, "TIMES.");
int number;
if (!int.TryParse(array[index - 1], out number))
{
//invalid number
}
Console.WriteLine(number);

If the input is reliable you can do a quicky with String.Split()...
int arrayLength = 0;
int timesindex = line.IndexOf("TIMES");
if (timesindex > 0)
{
string[] items = line.Split(new char[] {' '}, StringSplitOptions.RemoveEmptyEntries);
if (int.TryParse(items[items.Length - 2], out occursCount))
{
arrayLength = occursCount;
}
}
This method relies on the desired number being the second from last "word" in each line

If your strings are always the same format, with exactly five words or "sections" or whatever you want to call them, you could use:
int times = 0;
Int32.TryParse(line.Split(' ')[3], out times);
This would have to be more robust there's a chance the number may not exist in the string, or the string is in a completely different format.

Look at LastIndexOf combined with your timesindex. You can look for the space before the space before (timesindex-1), and then you have the two positions around the number.
int timesindex = line.IndexOf("TIMES");
int firstSpace = line.LastIndexOf(" ", timesindex-1);
string number = line.Substring(firstSpace, timesindex-firstSpace);
Though this might need some adjustments on the indexes, but that's the idea anyway

Try this
int timesindex = line.IndexOf("TIMES");
int happensindex = line.IndexOf("HAPPENS") + 7; //Add 7 cause HAPPEND is 7 chars long
if (timesindex > 0)
{
//Positon of the digit "5" in the first line
if (int.TryParse(line.Substring(happensindex, timesindex).trim(), out occursCount))
{
arrayLength = occursCount;
}
}

A Regex would be cleaner:
var regex = new Regex(#"(\d+)\sTIMES"); // match a number followed by whitespace then "TIMES"
string num = regex.Match(" 15 EMP_L_NAME HAPPENS 5 TIMES").Groups[1].ToString();
int val = int.Parse(num);

Using LINQ:
string[] lines = {"15 EMP_L_NAME HAPPENS 5,1 TIMES.", "40 SUP HAPPENS 12 TIMES. "};
var allValues = lines.Select(line =>
{
double temp;
var words = line.Split(new char[] {' '}, StringSplitOptions.RemoveEmptyEntries);
var value = words[Array.IndexOf(words,"TIMES.") - 1];
if (double.TryParse(value, out temp)) return temp;
else return 0;
}).ToList();
foreach (var value in allValues)
{
Console.WriteLine(value);
}
// Output:
// 5,1
// 12

You can use System.Text.RegularExpressions.Regex, i.e. a regular expression, in order to find a pattern in a string:
string input = "40 SUP HAPPENS 12 TIMES.";
Match match = Regex.Match(input, #"(?<=HAPPENS\s)\d+(?=\sTIMES)");
if (match.Success) {
Console.WriteLine(match.Value); '==> "12"
}
Explanation of the regular expression: It uses the general pattern (?<=prefix)find(?=suffix) in order to find a position between a prefix and suffix.
(?<=HAPPENS\s) Prefix consisting of "HAPPENS" plus a whitespace (\s)
\d+ A digit (\d) repeated one or more times (+)
(?=\sTIMES) Suffix consisting of a whitespace (\s) plus "TIMES"
If you only want to test for "TIMES" but not for "HAPPENS", you can just drop the first part:
Match match = Regex.Match(input, #"\d+(?=\sTIMES)");
Since you are using the same search pattern many times, it is advisable to create a Regex once instead of calling a static method:
Regex regex = new Regex(#"\d+(?=\sTIMES)");
// Use many times with different inputs
Match match = regex.Match(input);

Converting number to comma separated values

I need to convert numbers into a comma separated format to display in C#.
For Example:
1000 to 1,000
45000 to 45,000
150000 to 1,50,000
21545000 to 2,15,45,000
How to achieve this in C#?
I tried the below code:
int number = 1000;
number.ToString("#,##0");
But it is not working for lakhs.

I guess you can do this by creating a custom number format info for your needs
NumberFormatInfo nfo = new NumberFormatInfo();
nfo.CurrencyGroupSeparator = ",";
// you are interested in this part of controlling the group sizes
nfo.CurrencyGroupSizes = new int[] { 3, 2 };
nfo.CurrencySymbol = "";
Console.WriteLine(15000000.ToString("c0", nfo)); // prints 1,50,00,000
if specifically only for numbers then you could also do
nfo.NumberGroupSeparator = ",";
nfo.NumberGroupSizes = new int[] { 3, 2 };
Console.WriteLine(15000000.ToString("N0", nfo));

Here's a similar thread to yours add commas in thousands place for a number
and here's the solution that worked perfectly for me
String.Format("{0:n}", 1234);
String.Format("{0:n0}", 9876); // no decimals

If you want to be unique and do extra work that you don't have to here is a function I created for integer numbers you can place commas at whatever interval you want, just put 3 for a comma for each thousandths or you could alternatively do 2 or 6 or whatever you like.
public static string CommaInt(int Number,int Comma)
{
string IntegerNumber = Number.ToString();
string output="";
int q = IntegerNumber.Length % Comma;
int x = q==0?Comma:q;
int i = -1;
foreach (char y in IntegerNumber)
{
i++;
if (i == x) output += "," + y;
else if (i > Comma && (i-x) % Comma == 0) output += "," + y;
else output += y;
}
return output;
}

Have you tried:
ToString("#,##0.00")

Quick and dirty way:
Int32 number = 123456789;
String temp = String.Format(new CultureInfo("en-IN"), "{0:C0}", number);
//The above line will give Rs. 12,34,56,789. Remove the currency symbol
String indianFormatNumber = temp.Substring(3);

An easy solution would be to pass a format into the ToString() method:
string format = "$#,##0.00;-$#,##0.00;Zero";
decimal positiveMoney = 24508975.94m;
decimal negativeMoney = -34.78m;
decimal zeroMoney = 0m;
positiveMoney.ToString(format); //will return $24,508,975.94
negativeMoney.ToString(format); //will return -$34.78
zeroMoney.ToString(format); //will return Zero
Hope this helps,

Need code for addition of 2 numbers

I am having the numbers follows taken as strings
My actual number is 1234567890123456789
from this i have to separate it as s=12 s1=6789 s3=3456789012345
remaining as i said
I would like to add as follows
11+3, 2+4, 6+5, 7+6, 8+7, 9+8 such that the output should be as follows
4613579012345
Any help please

public static string CombineNumbers(string number1, string number2)
{
int length = number1.Length > number2.Length ? number1.Length : number2.Length;
string returnValue = string.Empty;
for (int i = 0; i < length; i++)
{
int n1 = i >= number1.Length ? 0 : int.Parse(number1.Substring(i,1));
int n2 = i >= number2.Length ? 0 : int.Parse(number2.Substring(i,1));
int sum = n1 + n2;
returnValue += sum < 10 ? sum : sum - 10;
}
return returnValue;
}

This sounds an awful lot like a homework problem, so I'm not giving code. Just think about what you need to do. You are saying that you need to take the first character off the front of two strings, parse them to ints, and add them together. Finally, take the result of the addition and append them to the end of a new string. If you write code that follows that path, it should work out fine.
EDIT: As Ralph pointed out, you'll also need to check for overflows. I didn't notice that when I started typing. Although, that shouldn't be too hard, since you're starting with a two one digit numbers. If the number is greater than 9, then you can just subtract 10 to bring it down to the proper one digit number.

How about this LINQish solution:
private string SumIt(string first, string second)
{
IEnumerable<char> left = first;
IEnumerable<char> right = second;
var sb = new StringBuilder();
var query = left.Zip(right, (l, r) => new { Left = l, Right = r })
.Select(chars => new { Left = int.Parse(chars.Left.ToString()),
Right = int.Parse(chars.Right.ToString()) })
.Select(numbers => (numbers.Left + numbers.Right) % 10);
foreach (var number in query)
{
sb.Append(number);
}
return sb.ToString();
}

Tried something:
public static string NumAdd(int iOne, int iTwo)
{
char[] strOne = iOne.ToString().ToCharArray();
char[] strTwo = iTwo.ToString().ToCharArray();
string strReturn = string.Empty;
for (int i = 0; i < strOne.Length; i++)
{
int iFirst = 0;
if (int.TryParse(strOne[i].ToString(), out iFirst))
{
int iSecond = 0;
if (int.TryParse(strTwo[i].ToString(), out iSecond))
{
strReturn += ((int)(iFirst + iSecond)).ToString();
}
}
// last one, add the remaining string
if (i + 1 == strOne.Length)
{
strReturn += iTwo.ToString().Substring(i+1);
break;
}
}
return strReturn;
}
You should call it like this:
string strBla = NumAdd(12345, 123456789);
This function works only if the first number is smaller than the second one. But this will help you to know how it is about.

In other words, you want to add two numbers treating the lesser number like it had zeroes to its right until it had the same amount of digits as the greater number.
Sounds like the problem at this point is simply a matter of finding out how much you need to multiply the smaller number by in order to reach the number of digits of the larger number.