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Splitting a string at first number and then returning 2 strings

Having some trouble adapting my splitting of a string into 2 parts to do it from the first number. It's currently splitting on the first space, but that won't work long term because cities have spaces in them too.
Current code:
var string = "Chicago 1234 Anytown, NY"
var commands = parameters.Split(new[] { ' ' }, 2);
var originCity = commands[0];
var destination = commands[1];
This works great for a city that has a single name, but I break on:
var string = "Los Angeles 1234 Anytown, NY"
I've tried several different approaches that I just haven't been able to work out. Any ideas on being able to return 2 strings as the following:
originCity = Los Angeles
destination = 1234 Anytown, NY

You can't use .Split() for this.
Instead, you need to find the index of the first number. You can use .indexOfAny() with an array of numbers (technically a char[] array) to do this.
int numberIndex = address.IndexOfAny("0123456789".ToCharArray())
You can then capture two substrings; One before the index, the other after.
string before = line.Substring(0, numberIndex);
string after = line.Substring(numberIndex);

You could use Regex. In the following, match is the first match in the regex results.
var match = Regex.Match(s, "[0-9]");
if (match.Success)
{
int index = match.Index;
originCity = s.Substring(0, index);
destination = s.Substring(index, s.Length - index);
}
Or you can do it yourself:
int index = 0;
foreach (char c in s)
{
int result;
if (int.TryParse(c, out result))
{
index = result;
break;
}
//or if (char.IsDigit()) { index = int.Parse(c); break; }
}
...

You should see if using a regular expression will do what you need here. At least with the sample data you're showing, the expression:
(\D+)(\d+)(\D+)
would group the results into non-numeric characters up to the first numeric character, the numeric characters until a non-numeric is encountered, and then the rest of the non-numeric characters. Here is how it would be used in code:
var pattern = #"(\D+)(\d+)(\D+)";
var input = "Los Angeles 1234 Anytown, NY";
var result = Regex.Match(input, pattern);
var city = result.Groups[1];
var destination = $"{result.Groups[2]} {result.Groups[3]}";
This falls apart in cases like 29 Palms, California or if the numbers would contain comma, decimal, etc so it is certainly not a silver bullet but I don't know your data and it may be ok for such a simple solution.

Regex to extract specific numbers in a String

string temp = "12345&refere?X=Assess9677125?Folder_id=35478";
I need to extract the number 12345 alone and I don't need the numbers 9677125 and 35478.
What regex can I use?

Here is the regex for extracting 5 digit number in the beginning of the string:
^(\d{5})&
If length is arbitrary:
^(\d+)&
If termination pattern is not always &:
^(\d+)[^\d]
Based on the Sayse's comment you can simply rewrite as:
^(\d+)
and in case of the termination is some number(for instance 999) then:
^(\d+)999

You don't need regex if you only want to extract the first number:
string temp = "12345&refere?X=Assess9677125?Folder_id=35478";
int first = Int32.Parse(String.Join("", temp.TakeWhile(c => Char.IsDigit(c))));
Console.WriteLine(first); // 12345

If the number you want is always at the beginning of the string and terminated by an ampersand (&) you don't need a regex at all. Just split the string on the ampersand and get the first element of the resulting array:
String temp = "12345&refere?X=Assess9677125?Folder_id=35478";
var splitArray = String.Split('&', temp);
var number = splitArray[0]; // returns 12345
Alternatively, you can get the index of the ampersand and substring up to that point:
String temp = "12345&refere?X=Assess9677125?Folder_id=35478";
var ampersandIndex = temp.IndexOf("&");
var number = temp.SubString(0, ampersandIndex); // returns 12345

From what you haven given us this is fairly simple:
var regex = new Regex(#"^(?<number>\d+)&");
var match = regex.Match("12345&refere?X=Assess9677125?Folder_id=35478");
if (match.Success)
{
var number = int.Parse(match.Groups["number"].Value);
}
Edit: Of course you can replace the argument of new Regex with any of the combinations Giorgi has given.

String splitting with a special structure

I have strings of the following form:
str = "[int]:[int],[int]:[int],[int]:[int],[int]:[int], ..." (for undefined number of times).
What I did was this:
string[] str_split = str.Split(',');
for( int i = 0; i < str_split.Length; i++ )
{
string[] str_split2 = str_split[i].Split(':');
}
Unfortunately this breaks when some of the numbers have extra ',' inside a number. For example, we have something like this:
695,000:14,306,000:12,136000:12,363000:6
in which the followings are the numbers, ordered from the left to the right:
695,000
14
306,000
12
136000
12
363000
6
How can I resolve this string splitting problem?

If it is the case that only the number to the left of the colon separator can contain commas, then you could simply express this as:
string s = "695,000:14,306,000:12,136000:12,363000:6";
var parts = Regex.Split(s, #":|(?<=:\d+),");
The regex pattern, which identifies the separators, reads: "any colon, or any comma that follows a colon and a sequence of digits (but not another comma)".

A simple solution is split using : as delimiter. The resultant array will have numbers of the format [int],[int]. Parse through the array and split each entry using , as the delimiter. This will give you an array of [int] numbers.

It might not be the best way to do it and it might not work all the time but here's what I'd do.
string[] leftRightDoubles = str.Split(':');
foreach(string substring in leftRightDoubles){
string[] indivNumbers = str.Split(',');
//if indivNumbers.Length == 2, you know that these two are separate numbers
//if indivNumbers.Length > 2, use heuristics to determine which parts belong to which number
if(indivNumbers.Length > 2) {
for(int i = 0, i < indivNumbers.Length, i++) {
if(indivNumbers[i] != '000') { //Or use some other heuristic
//It's a new number
} else {
//It's the rest of previous number
}
}
}
}
//It's sort of pseudocode with comments (haven't touched C# in a while so I don't want to write full C# code)

Get multiple numbers from a string

I have strings like
AS_!SD 2453iur ks#d9304-52kasd
I need to get the 2 frist numbres of the string:
for that case will be:
2453 and 9304
I don't have any delimiter in the string to try a split, and the length of the numbers and string is variable, I'm working in C# framework 4.0 in a WPF.
thanks for the help, and sorry for my bad english

This solution will take two first numbers, each can have any number of digits
string s = "AS_!SD 2453iur ks#d9304-52kasd";
MatchCollection matches = Regex.Matches(s, #"\d+");
string[] result = matches.Cast<Match>()
.Take(2)
.Select(match => match.Value)
.ToArray();
Console.WriteLine( string.Join(Environment.NewLine, result) );
will print
2453
9304
you can parse them to int[] by result.Select(int.Parse).ToArray();

You can loop chars of your string parsing them, if you got a exception thats a letter if not is a number them you must to have a list to add this two numbers, and a counter to limitate this.
follow a pseudocode:
for char in string:
if counter == 2:
stop loop
if parse gets exception
continue
else
loop again in samestring stating this point
if parse gets exception
stop loop
else add char to list

Alternatively you can use the ASCII encoding:
string value = "AS_!SD 2453iur ks#d9304-52kasd";
byte zero = 48; // 0
byte nine = 57; // 9
byte[] asciiBytes = Encoding.ASCII.GetBytes(value);
byte[] asciiNumbers = asciiBytes.Where(b => b >= zero && b <= nine)
.ToArray();
char[] numbers = Encoding.ASCII.GetChars(asciiNumbers);
// OR
string numbersString = Encoding.ASCII.GetString(asciiNumbers);
//First two number from char array
int aNum = Convert.ToInt32(numbers[0]);
int bNum = Convert.ToInt32(numbers[1]);
//First two number from string
string aString = numbersString.Substring(0,2);

String parsing, extracting numbers and letters

What's the easiest way to parse a string and extract a number and a letter? I have string that can be in the following format (number|letter or letter|number), i.e "10A", "B5", "C10", "1G", etc.
I need to extract the 2 parts, i.e. "10A" -> "10" and "A".
Update: Thanks to everyone for all the excellent answers

Easiest way is probably to use regular expressions.
((?<number>\d+)(?<letter>[a-zA-Z])|(?<letter>[a-zA-Z])(?<number>\d+))
You can then match it with your string and extract the value from the groups.
Match match = regex.Match("10A");
string letter = match.Groups["letter"].Value;
int number = int.Parse(match.Groups["number"].Value);

The easiest and fastest is to use simple string operations. Use the IsDigit method to check where the letter is, and parse the rest of the string to a number:
char letter = str[0];
int index = 1;
if (Char.IsDigit(letter)) {
letter = str[str.Length - 1];
index = 0;
}
int number = int.Parse(str.Substring(index, str.Length - 1));

Just to be different:
string number = input.Trim("ABCDEFGHIJKLMNOPQRSTUVWXYZ".ToCharArray());
string letter = input.Trim("0123456789".ToCharArray());

char letter = str.Single(c => char.IsLetter(c));
int num = int.Parse(new string(str.Where(c => char.IsDigit(c)).ToArray()));
This solution is not terribly strict (it would allow things like "5A2" and return 'A' and 52) but it may be fine for your purposes.

Here is how I would approach this. You can step through this and put gc1["letter"], gc1["number"], gc2["letter"], and gc2["number"] in the watch window to see that it worked (step just past the last line of code here, of course).
The regular epxression will take either pattern requiring one or more letter and number in each case.
Regex pattern = new Regex("^(?<letter>[a-zA-Z]+)(?<number>[0-9]+)|(?<number>[0-9]+)(?<letter>[a-zA-Z]+)$");
string s1 = "12A";
string s2 = "B45";
Match m1 = pattern.Match(s1);
Match m2 = pattern.Match(s2);
GroupCollection gc1 = m1.Groups;
GroupCollection gc2 = m2.Groups;

Using Sprache and some Linq kung-fu:
var tagParser =
from a in Parse.Number.Or(Parse.Letter.Once().Text())
from b in Parse.Letter.Once().Text().Or(Parse.Number)
select char.IsDigit(a[0]) ?
new{Number=a, Letter=b} : new{Number=b, Letter=a};
var tag1 = tagParser.Parse("10A");
var tag2 = tagParser.Parse("A10");
tag1.Letter; // should be A
tag1.Number; // should be 10
tag2.Letter; // should be A
tag2.Number; // should be 10
/* Output:
A
10
A
10
*/