Develop Reference

Replace string occurrences with list entries

I've been wrapping my head around this to find an "elegant" solution but I'm not quite satisfied with it.
Possible input strings:
foo () bar ()
() bar
foo
()()foo () bar
There can be "unlimited" brackets and optional, non-bracket text inbetween the brackets. The content of these empty brackets are supposed to filled with data taking from a List<string> in the order of the list entries. If there no entries or not sufficient entries the brackets are untouched.
Possible string replacements:
foo () bar () replaced with x, y will result in foo (x) bar (y)
foo () bar () replaced with x will result in foo (x) bar ()
foo () bar () replaced with x, y, z will result in foo (x) bar (y)
I hope you get the idea.
Solutions:
The solutions I had so far are fiddling around with indexes and a lot special logic to handle the different cases.
I wondered if there is a more elegant solution with, for example regex. Maybe I'm too close at the problem right now and there is a simple solution :-)
Here is an approach I'm not really happy about (readability / easy to understand):
var guiIdentifierIndex = 0;
var guiIdentifierList = new List<string>{"x", "y", "z", "x", "y"};
var sourcePathItem = "foo ()";
string targetString = "";
var splittedPath = sourcePathItem.Split(new string[] { BRACKETS }, StringSplitOptions.None);
for (int index = 0; index < splittedPath.Length; index++)
{
var subPath = splittedPath[index];
var guiIdentifier = string.Empty;
if (guiIdentifierIndex < guiIdentifierList.Count)
{
guiIdentifier = guiIdentifierList[guiIdentifierIndex];
guiIdentifierIndex++;
}
targetString += subPath;
if (index < splittedPath.Length - 1)
targetString += string.Format("({0})", guiIdentifier);
}
http://volatileread.com/utilitylibrary/snippetcompiler?id=22718

You can use regular expressions, e.g.
String source = "foo () bar ()";
var guiIdentifierList = new List<String> {
"x", "y", "z", "x", "y" };
int guiIdentifierIndex = 0;
// result == "foo (x) bar (y)"
String result = Regex.Replace(source, #"\(\)", (MatchEvaluator) (
(match) => "(" + (guiIdentifierIndex < guiIdentifierList.Count
? guiIdentifierList[guiIdentifierIndex++]
: "") + ")"
));

Split the replacement string (x,y,z) on commas, then loop through the resulting array replacing the first occurrence of () by the appropriate value.
This link shows you how to replace the first instance : Replace first occurrence of pattern in a string

How about this:
var template = "foo () bar ()";
var replacements = new[] {"x", "y", "z"};
var components = template.Split(new []{"()"}, StringSplitOptions.RemoveEmptyEntries);
var sb = new StringBuilder();
var replacementCount = replacements.Count();
for (int i = 0; i < components.Count(); i++)
{
var value = i >= replacementCount ? String.Empty : replacements[i];
sb.AppendFormat("{0}({1})", components[i], value);
}
var substitutedTemplate = sb.ToString();

I would do this way:
List<string> guiIdentifiers = new List<string>{"x", "y", "z", "x", "y"};
string input = "foo () () () () () ()";
string[] splitPath = Regex.Split(input, #"(\(\))");
for (int i = 0; i < splitPath.Length; i++)
{
if (splitPath[i] == "()" && guiIdentifiers.Count > 0)
{
splitPath[i] = string.Format("({0})", guiIdentifiers.First());
guiIdentifiers.Remove(guiIdentifiers.First());
}
}
string result = string.Join("", splitPath);
And note that split is an irregular verb that has the third form as split also, splitted is really weird and I do not recommend you to use.

var numbers = new List<string>(new[] { "1", "2", "3" });
string original = "() test ()()";
String[] tokens = original.Split(new [] {"()"}, StringSplitOptions.None);
if (tokens.Count() >= numbers.Count())
return original;
return string.Concat(tokens.Take(tokens.Count() - 1)
.Select((t, i) => t + "(" + numbers[i] + ")"));

You could try to construct the target string in one foor loop like this ("Copy and Substitute")
EDIT: Now with "lookahead" to not substitute if closing bracket is missing.
var guiIdentifierIndex = 0;
var guiIdentifierList = new List<string> { "x", "y", "z" };
var sourcePathItem = "foo () bar () func()";
string targetString = "";
int srcIndex = 0;
foreach(char c in sourcePathItem)
{
targetString += c;
char lookahead = srcIndex < sourcePathItem.Length - 1 ? sourcePathItem[++srcIndex] : ' ';
if (c == '(' && lookahead == ')'
&& guiIdentifierIndex < guiIdentifierList.Count)
{
targetString += guiIdentifierList[guiIdentifierIndex++];
}
}
Console.WriteLine("Target: " + targetString);
This substitutes foo () bar () with x, y to foo (x) bar (y).
Generally I think using a Stringbuilder for the target string would be better when sourcePathItem and guidIdentifierList is getting bigger. e.g. less resource usage
Greetings

Hi you could used Regex groups. https://msdn.microsoft.com/en-us/library/ewy2t5e0(v=vs.110).aspx
The code below matches on ( and create a regex group which you could the used to replace.
var sourcePathItem = "()()foo () bar";
var q = new Queue<string>(new string[]{ "x", "y", "z", "x", "y" });
var replaced = Regex.Replace(sourcePathItem, #"\(", m =>
(m.Groups[1].Value + "(" + q.Dequeue())
);

StringBuilder sb = new StringBuilder();
String[] parts = sourcePathItem.Split(new String[]{"()"}, StringSplitOptions.None);
for (Int32 i = 0; i < parts.Length; i++){
sb.Append(parts[i]);
if (i < guiIdentifierList.Count && i + 1 < parts.Length)
sb.Append("(" + guiIdentifierList[i] + ")");
}
var result = sb.ToString();

C# Replace with mixed values

What I am looking for is a way to replicate PHP str_replace() function in C#.
In PHP code It would look like:
$string = 'This is my demo y string!';
$search_for = array("y","x","z");
$replace_with = array("1","2","3");
if( str_replace($search_for,$replace_with,$string) ) {
$changed = true;
};
Where the y is changed to 1, x changed to 2 etc., And if anything was changed then set the variable changed or do any other code.
How to do the same in C#?
Thank you.

You can chain your string replaces like so:
var result = myString.Replace("y", "1").Replace("x", "2").Replace("z", "3");
That should do what you are looking for. An alternative approach if you had arrays with the replacements would be:
var originalChar = new List<char> { '1', '2', '3' };
var replaceWith = new List<char> { 'x', 'y', 'z' };
originalChar.ForEach(x => myString = myString.Replace(x, replaceWith[originalChar.IndexOf(x)]));
This could probably be more efficient but you get the idea.
Checking for a change:
As noted in the comments, checking for a change is as simple as checking if the original and the modified string are no longer equal:
var changed = (result != myString);

You can do it using LINQ and a Dictionary
var mappings = new Dictionary<char,char> { {'y', '1' }, { 'x', '2'} , {'z','3'}};
var newChars = inputString
.Select(x =>
{
if (mappings.ContainsKey(x))
return mappings[x];
return x;
})
.ToArray();
var output = new string(newChars);
bool changed = !(output == inputString);

This is a straightforward port, although I think it would be better to use C# the "conventional" way.
string inputString = "This is my demoy y string!";
string[] searchFor = new string[] { "y", "x", "z" }; // or char[] if you prefer
string[] replaceWith = new string[] { "1", "2", "3" };
if (ArrayReplace(searchFor, replaceWith, ref inputString))
{
bool changed = true;
}
bool ArrayReplace(string[] searchFor, string[] replaceWith, ref string inputString)
{
string copy = inputString;
for (int i = 0; i < searchFor.Length && i < replaceWith.Length; i++)
{
inputString = inputString.Replace(searchFor[i], replaceWith[i]);
}
return copy != inputString;
}

c# array help on sorting

First of all sorry for my mistakes in English its not my primary language
i have a problem , i have a array like following
string[] arr1 = new string[] {
"Pakistan:4,India:3,USA:2,Iran:1,UK:0",
"Pakistan:4,India:3,USA:2,Iran:1,UK:0",
"India:4,USA:3,Iran:2,UK:1,Pakistan:0"
};
now i just want to know that how many times Pakistan comes with 1 ,
how many times with 2 , 3 , 4
and i need to know this about all India , USA , Iran , UK
Thanks in advance , you guys are my last hope .

This linq will convert the array into a Dictionary>, where the outer dictionary contains the countries names, and inner dictionaries will contain the ocurrence number (the number after ':') and the count for each ocurrence.
string[] arr1 = new string[]
{
"Pakistan:4,India:3,USA:2,Iran:1,UK:0",
"Pakistan:4,India:3,USA:2,Iran:1,UK:0",
"India:4,USA:3,Iran:2,UK:1,Pakistan:0"
};
var count = arr1
.SelectMany(s => s.Split(new[] { ',' }, StringSplitOptions.RemoveEmptyEntries))
.GroupBy(s => s.Split(':')[0], s => s.Split(':')[1])
.ToDictionary(g => g.Key,
g =>
{
var items = g.Distinct();
var result = new Dictionary<String, int>();
foreach (var item in items)
result[item] = g.Count(gitem => gitem == item);
return result;
});
// print the result
foreach(var country in count.Keys)
{
foreach(var ocurrence in count[country].Keys)
{
Console.WriteLine("{0} : {1} = {2}", country, ocurrence, count[country][ocurrence]);
}
}

I would use the String.Split(char[]) method and the String.SubString(int, int) method to inspect every 'country' inside your array and to get the number postfix of each country.
Try the following:
(The following code is now compiled and tested.)
Use a simple data structure to facilitate the task of holding the result of your operation.
public struct Result {
string Country { get; set; }
int Number { get; set; }
int Occurrences { get; set; }
}
// define what countries you are dealing with
string[] countries = new string[] { "Pakistan", "India", "USA", "Iran", "UK", }
Method to provide the overall result:
public static Result[] IterateOverAllCountries () {
// range of numbers forming the postfix of your country strings
int numbersToLookFor = 4;
// provide an array that stores all the local results
// numbersToLookFor + 1 to respect that numbers are starting with 0
Result[] result = new Result[countries.Length * (numbersToLookFor + 1)];
string currentCountry;
int c = 0;
// iterate over all countries
for (int i = 0; i < countries.Length; i++) {
currentCountry = countries[i];
int j = 0;
// do that for every number beginning with 0
// (according to your question)
int localResult;
while (j <= numbersToLookFor) {
localResult = FindCountryPosition(currentCountry, j);
// add another result to the array of all results
result[c] = new Result() { Country = currentCountry, Number = j, Occurrences = localResult };
j++;
c++;
}
}
return result;
}
Method to provide a local result:
// iterate over the whole array and search the
// occurrences of one particular country with one postfix number
public static int FindCountryPosition (string country, int number) {
int result = 0;
string[] subArray;
for (int i = 0; i < arr1.Length; i++) {
subArray = arr1[i].Split(',');
string current;
for (int j = 0; j < subArray.Length; j++) {
current = subArray[j];
if (
current.Equals(country + ":" + number) &&
current.Substring(current.Length - 1, 1).Equals(number + "")
)
result++;
}
}
return result;
}
The following should enable you to run the algorithm
// define what countries you are dealing with
static string[] countries = new string[] { "Pakistan", "India", "USA", "Iran", "UK", };
static string[] arr1 = new string[] {
"Pakistan:4,India:3,USA:2,Iran:1,UK:0",
"Pakistan:4,India:3,USA:2,Iran:1,UK:0",
"India:4,USA:3,Iran:2,UK:1,Pakistan:0"
};
static void Main (string[] args) {
Result[] r = IterateOverAllCountries();
}

The data structure you are using is not rich enough to provide you with that information. Hence you need to parse your string and create a new data structure to be able to provide (sring[][]):
string[] arr1 = new string[] {
"Pakistan,India,USA,Iran,UK",
"Pakistan,India,USA,Iran,UK",
"India,USA,Iran,UK,Pakistan"
};
string[][] richerArray = arr1.Select(x=> x.Split('\'')).ToArray();
var countPakistanIsFirst = richerArray.Select(x=>x[0] == "Pakistan").Count();
UPDATE
You seem to have changed your question. The answer applies to the original question.

Combining arrays of strings together

I'm looking to combine the contents of two string arrays, into a new list that has the contents of both joined together.
string[] days = { "Mon", "Tue", "Wed" };
string[] months = { "Jan", "Feb", "Mar" };
// I want the output to be a list with the contents
// "Mon Jan", "Mon Feb", "Mon Mar", "Tue Jan", "Tue Feb" etc...
How can I do it ? For when it's only two arrays, the following works and is easy enough:
List<string> CombineWords(string[] wordsOne, string[] wordsTwo)
{
var combinedWords = new List<string>();
foreach (var wordOne in wordsOne)
{
foreach (string wordTwo in wordsTwo)
{
combinedWords.Add(wordOne + " " + wordTwo);
}
}
return combinedWords;
}
But I'd like to be able to pass varying numbers of arrays in (i.e. to have a method with the signature below) and have it still work.
List<string> CombineWords(params string[][] arraysOfWords)
{
// what needs to go here ?
}
Or some other solution would be great. If it's possible to do this simply with Linq, even better!

What you want to do is actually a cartesian product of all the arrays of words, then join the words with spaces. Eric Lippert has a simple implementation of a Linq cartesian product here. You can use it to implement CombineWords:
List<string> CombineWords(params string[][] arraysOfWords)
{
return CartesianProduct(arraysOfWords)
.Select(x => string.Join(" ", x))
.ToList();
}

To cross join on any amount of arrays of strings:
// Define other methods and classes here
List<string> CombineWords(params string[][] arraysOfWords)
{
if (arraysOfWords.Length == 0)
return new List<string>();
IEnumerable<string> result = arraysOfWords[0];
foreach( string[] words in arraysOfWords.Skip(1) )
{
var tempWords = words;
result = from r in result
from w in tempWords
select string.Concat(r, " ", w);
}
return result.ToList();
}

Code below works for any number of arrays (and uses linq to some degree):
List<string> CombineWords(params string[][] wordsToCombine)
{
if (wordsToCombine.Length == 0)
return new List<string>();
IEnumerable<string> combinedWords = wordsToCombine[0].ToList();
for (int i = 1; i < wordsToCombine.Length; ++i)
{
var temp = i;
combinedWords = (from x in combinedWords from y in wordsToCombine[temp]
select x + " " + y);
}
return combinedWords.ToList();
}

public static List<string> CombineWords(params string[][] arraysOfWords)
{
var strings = new List<string>();
if (arraysOfWords.Length == 0)
{
return strings;
}
Action<string, int> combineWordsInternal = null;
combineWordsInternal = (baseString, index) =>
{
foreach (var str in arraysOfWords[index])
{
string str2 = baseString + " " + str;
if (index + 1 < arraysOfWords.Length)
{
combineWordsInternal(str2, index + 1);
}
else
{
strings.Add(str2);
}
}
};
combineWordsInternal(string.Empty, 0);
return strings;
}
Second try... I'm not able to do it in LINQ... A little too much complex to linquize correctly :-)
I'm using a local anonymous function (and showing that it's quite complex to recurse on anonymous functions, because you have to declare them separately)

This is a non-recursive solution which buffers strings as it progresses, to reduce the number of concatenations. Therefore it should also be usable for more arrays.
It also preserves your desired order - the items in the first array will always be at the beginning of the resulting string.
var s1 = new string[] { "A", "B", "C" };
var s2 = new string[] { "1", "2", "3", "4" };
var s3 = new string[] { "-", "!", "?" };
var res = Combine(s1, s2, s3);
And the function in question:
private List<string> Combine(params string[][] arrays)
{
if (arrays.Length == 1)
{
// The trivial case - exit.
return new List<string>(arrays[0]);
}
IEnumerable<string> last = arrays[arrays.Length - 1];
// Build from the last array, progress forward
for (int i = arrays.Length - 2; i >= 0; i--)
{
var buffer = new List<string>();
var current = arrays[i];
foreach (var head in current)
{
foreach (var tail in last)
{
// Concatenate with the desired space.
buffer.Add(head + " " + tail);
}
}
last = buffer;
}
return (List<string>)last;
}

Could you try this method ?
static List<string> CombineWords(string[] wordsOne, string[] wordsTwo)
{
var combinedWords = new List<string>();
for(int x = 0; (x <= wordsOne.Length - 1); ++x)
{
for(int y = 0; (x <= wordsTwo.Length - 1); ++y)
{
combinedWords.Add(string.Format("{0} {1}", wordsOne[x], wordsTwo[y]));
}
}
return combinedWords;
}
Kris

Easiest way to parse a comma delimited string to some kind of object I can loop through to access the individual values?

What is the easiest way to parse a comma delimited string list of values into some kind of object that I can loop through, so that I can access the individual values easily?
example string: "0, 10, 20, 30, 100, 200"
I'm a bit new to C#, so forgive me for asking a simple question like this. Thanks.

there are gotchas with this - but ultimately the simplest way will be to use
string s = [yourlongstring];
string[] values = s.Split(',');
If the number of commas and entries isn't important, and you want to get rid of 'empty' values then you can use
string[] values = s.Split(",".ToCharArray(), StringSplitOptions.RemoveEmptyEntries);
One thing, though - this will keep any whitespace before and after your strings. You could use a bit of Linq magic to solve that:
string[] values = s.Split(',').Select(sValue => sValue.Trim()).ToArray();
That's if you're using .Net 3.5 and you have the using System.Linq declaration at the top of your source file.

var stringToSplit = "0, 10, 20, 30, 100, 200";
// To parse your string
var elements = test.Split(new[]
{ ',' }, System.StringSplitOptions.RemoveEmptyEntries);
// To Loop through
foreach (string items in elements)
{
// enjoy
}

Use Linq, it is a very quick and easy way.
string mystring = "0, 10, 20, 30, 100, 200";
var query = from val in mystring.Split(',')
select int.Parse(val);
foreach (int num in query)
{
Console.WriteLine(num);
}

The pattern matches all non-digit characters. This will restrict you to non-negative integers, but for your example it will be more than sufficient.
string input = "0, 10, 20, 30, 100, 200";
Regex.Split(input, #"\D+");

I think it's better to use the Microsoft.VisualBasic.FileIO.TextFieldParser Class
if you're working with comma separated values text files.

Sometimes the columns will have commas within themselves, such as:
"Some item", "Another Item", "Also, One more item"
In these cases, splitting on "," will break some columns. Maybe an easier way, but I just made my own method (as a bonus, handles spaces after commas and returns an IList):
private IList<string> GetColumns(string columns)
{
IList<string> list = new List<string>();
if (!string.IsNullOrWhiteSpace(columns))
{
if (columns[0] != '\"')
{
// treat as just one item
list.Add(columns);
}
else
{
bool gettingItemName = true;
bool justChanged = false;
string itemName = string.Empty;
for (int index = 1; index < columns.Length; index++)
{
justChanged = false;
if (subIndustries[index] == '\"')
{
gettingItemName = !gettingItemName;
justChanged = true;
}
if ((gettingItemName == false) &&
(justChanged == true))
{
list.Add(itemName);
itemName = string.Empty;
justChanged = false;
}
if ((gettingItemName == true) && (justChanged == false))
{
itemName += columns[index];
}
}
}
}
return list;
}

Use a loop on the split values
string values = "0,1,2,3,4,5,6,7,8,9";
foreach(string value in values.split(','))
{
//do something with individual value
}