C# String Methods

In this tutorial, we'll learn about some common string methods in C#.

Equal

This method returns whether the two string objects have the same value or not.

string text = "Dev.to";
string text2 = "Devto";

if(text.Equals(text2))
{
    Console.Write("Yes!");
}
else
{
    Console.Write("No");
}

// Outputs - No

Contains

This method returns true if the given string is present in the source string.

string text = "Dev.to is the best platform for developers";

if(text.Contains("best"))
{
    Console.Write("Yes!");
}
else
{
    Console.Write("No");
}

// Outputs - Yes!

You can also check if a character is present in the string, for example

text.Contains('b');

Compare

This method compares two strings and returns an integer. It returns

less than zero if the first substring precedes the second substring in the sort order.

zero if the two strings are equal

more than zero if the first substring follows the second substring in the sort order.

string text = "Dev.to";
string text2 = "Devto";

Console.Write(String.Compare(text, text2)); // -1

IndexOf

This method returns the first index of a character or substring in a source string. If the character or substring is not present in the source, it returns -1.

string text = "Dev.to";

Console.WriteLine(text.IndexOf('.')); // 3
Console.WriteLine(text.IndexOf('a')); // -1

IsNullOrEmpty

This method indicates whether the given string is null or an empty string ("").

string text = "";
if(String.IsNullOrEmpty(text))
{
    Console.Write("Yes");
}
else
{
    Console.Write("No");
}

// Outputs - Yes

Split

This method splits the string into an array of strings or characters by a delimiter.

string text = "C# provides support for OOP.";

foreach (var item in text.Split(' '))
{
    Console.WriteLine(item);
}

/* Outputs
C#
provides
support 
for     
OOP. */

Join

This method concatenates the elements of the specified array or collection using the given separator.

string[] elements = {"This", "is", "my", "blog."};

Console.Write(String.Join(' ', elements));

// Outputs - This is my blog.

Trim

This method removes all the leading and trailing occurences of the specified character or a set of characters.

string text = "----C# provides support for OOP.----";

Console.Write(text.Trim('-'));

Replace

This method returns a new string after replacing all the occurrences of a specified character or string with another specified character or string.

string text = "C# provides support for OOP.";

Console.Write(text.Replace(' ', '_')); // C#_provides_support_for_OOP.

Format

This method is used to convert variables to strings and insert them into another string.

string name = "John";
int age = 32;
string text = String.Format("{0} is {1} years old", name, age);            
Console.Write(text);

// John is 32 years old