Introduction

In C#, we have a primitive type specifically for string. You don’t have to use char array as in C++. We also have a class “String” in C# for extra string operations.

Note
String is a primitive type and String is a class. For better understanding, know that String class is bold.

You can create a string in any of the below methods:

  1. string firstName;
  2. firstName = null;
  3. firstName = string.Empty;
  4. firstName = "";
  5. firstName = "Hello";
  6. char[] letters = { 'C', ' ', 'S', 'h', 'a', 'r', 'p' };
  7. string objString = new string(letters);
C#

Concatenation

  1. string lastName = "World";
  2. string output = firstName + lastName;
  3. Console.WriteLine("Output = " + output);
  4. output = firstName + " " + lastName;
  5. Console.WriteLine("Output = " + output);
C#

Join String Array

Syntax : String.Join(delimiter, string_Array);

  1. string[] joinArray = { "String", "Join", "Done", "Successfully" };
  2. string joinOutput = String.Join("-", joinArray);
  3. Console.WriteLine("Output = " + joinOutput);
  4. string joinOutput2 = String.Join(" ", joinArray);
  5. Console.WriteLine("Output = " + joinOutput2);
  6. string joinOutput3 = String.Join(" ", joinArray) + ".";
  7. Console.WriteLine("Output = " + joinOutput3);
C#

Split String Data into Array

  1. string splitableContent = "Hello from Karthi";
  2. string[] splitContent = splitableContent.Split(' ');
  3. foreach (string word in splitContent)
  4. {
  5. Console.WriteLine(word);
  6. }
C#

Length & Count

  1. string abc = "Hello";
  2. char[] lettersArray = { 'C', ' ', 'S', 'h', 'a', 'r', 'p' };
  3. Console.WriteLine(abc.Length);
  4. Console.WriteLine(lettersArray.Count());

Length is a property of string & Array.

Output

Length = 5

Count = 7

Format String Value

Format method of String Class is used to format string value based on your needs.

  1. DateTime todayDate = DateTime.Now;
  2. string formattedVal = String.Format("Time: {0:t} and Date : {0:D}", todayDate);
  3. Console.WriteLine("Format String = " + formattedVal);
C#

Copy String

  1. string a = "Hai";
  2. string b = string.Copy(a);
  3. Console.WriteLine("A = " + a);
  4. Console.WriteLine("B = " + b);
C#

Compare String

Compare method of string compares two string and returns the 0, 1 or -1.

If both are the same, it returns 0.

If the first one is bigger, it returns 1.

If the second one is bigger, it returns -1.

Syntax

  1. int Compare (string a, string b);
  2. int Compare(string a, string b, true);

The third parameter is used and set to true when you want to compare two strings ignoring case.

  1. //Compare
  2. string sa1 = "Hello";
  3. string sa2 = "hello";
  4. Console.WriteLine("Compare = " + string.Compare(sa1, sa2));
  5. Console.WriteLine("Compare = " + string.Compare(sa1, sa2, true));
C#

String Equality

Equals method checks whether two strings are the same and returns true or false.

  1. string se1 = "hello";
  2. string se2 = "hello";
  3. Console.WriteLine("Equals = " + string.Equals(se1, se2));
  4. Console.WriteLine("Equals 2 = " + se1.Equals(se2));
C#

Contains & EndsWith

Contains method checks whether the string contains the specified string.

EndsWith method checks whether the string ends with the specified string.

  1. string stringObj = "this is a big sentence with number one";
  2. Console.WriteLine("Contains 'one' = " + stringObj.Contains("one"));
  3. Console.WriteLine("EndsWith 'one' = " + stringObj.EndsWith("one"));
C#