useful nippets C# for advanced

print array in one line
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Console.WriteLine(string.Join(", ", arr));
Console.WriteLine("[{0}]", string.Join(", ", arr));
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replace text using regex
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string text = Regex.Replace(sb.ToString(), @"\s+", " ");
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string to int array
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int[] arr = Console.ReadLine().Split(' ').Select

(int.Parse).ToArray();
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list all elements in array
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int[] arr = { 1 , 2 , 3 };
arr.ToList().ForEach(a => Console.WriteLine(a));
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find if a number is float/decimal/double or not
--------
if (item % 1 == 0)
{
    // it is not
}
else
{
    // it is
}
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Remove all numbers that are bigger then `n` in a list
--------
list.RemoveAll(p => p <= `n`);
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Select and order by elements in list
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var results = list.Where(i => i % 2 == 0).OrderBy(p => p);
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Print only half all elements in a list
---------
list.ForEach(p => Console.WriteLine(p/2));
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Split and remove all white spaces in a list
---------
List<int> numsList = Console.ReadLine().Split(' ').Where(s

=> !string.IsNullOrWhiteSpace(s)).Select(p => int.Parse

(p)).ToList();
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Split string by multiple character delimiter (new char[]

{'.', '?'})
---------
List<string> input = Console.ReadLine().Split(new string[]

{ " ", "," },

StringSplitOptions.RemoveEmptyEntries).ToList();
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Match collection !!!!
---------
MatchCollection cleanData = Regex.Matches(input, pattern);
foreach (Match match in cleanData)
{
Console.WriteLine("Area Code: {0}", match.Groups[1].Value);
}
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Split using regex
---------
string pattern = @"\s+";
string[] substrings = Regex.Split(input, pattern);
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Replace using regex
---------
string athlete = Regex.Replace(tokens[0].Trim(), @"\s+", "

");
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Sort ints Asc or Desc
---------
li.Sort((a, b) => a.CompareTo(b)); // ascending sort
li.Sort((a, b) => -1* a.CompareTo(b)); // descending sort
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Sort by name and if the name is the same order by age

(OrderBy || OrderByDesending)
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var pets = new [] { new { Name="Rex", Age=3 } };
var sorted = pets.OrderBy(pet => pet.Name).ThenBy(pet =>

pet.Age);
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Output dictionary by order of the values
---------
foreach (KeyValuePair<string, int> item in

dictionary.OrderByDescending(key => key.Value))
{
   Console.WriteLine("{0} - {1}", item.Key, item.Value);
}
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using LINQ sorting and ordering arrays
---------
int[] numbers = { 5, 4, 1, 3, 9, 8, 6, 7, 2, 0 };
var result = numbers.Where(num => num < 4 && num % 2 == 0).

OrderBy(num => num).Select(num => num * 2);
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put in a list all posible pairs
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string[] towns = { "Sofia", "Varna", "Pleven", "Ruse" };
var pairs = (from firstTown in towns
    from secondTown in towns
    select new { First = firstTown, Second =

secondTown}).ToList();
foreach (var townPair in pairs) {
    Console.WriteLine("{0} : {1}", townPair.First,

townPair.Second);
    }
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LINQ:
Operations
-----------
Where() - Searches by given condition
First() / FirstOrDefault() - Gets the first element
Last() / LastOrDefault() - Gets the last element
Select() / Cast() - Makes projection (conversion) to other

type
OrderBy() / ThenBy() / OrderByDescending() - Orders a

collection
Any() - Checks if any element matches a condition
All() - Checks if all elements match a condition
ToArray()/ToList()/AsEnumerable() - Converts the collection
Reverse() - Reverses a collection

Aggregation Methods
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Average() - Calculates the average value of a collection
Count() - Counts the elements in a collection
Max() - Determines the maximum value of a collection
Sum() - Sums the value in a collecition
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How can I detect if this dictionary key exists?
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if (dict.ContainsKey(key)) { ... }
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