String in C# | Chapter 5

C# String & string Manipulation

String Basics

In C#, a string is a sequence of characters stored as a single data type. Strings are immutable, meaning any operation that appears to modify a string actually creates a new string. string and String both can be used to represent string bath are same string preffered.

String Concatenation

Concatenation is the process of combining two or more strings into one. You can use the + operator to concatenate strings.

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string name = "CFD";
int age = 0;
string message = "My name is " + name + " and I am " + age + " years old.";
Console.WriteLine(message); // Outputs: My name is CFD and I am 0 years old.

String Interpolation

String interpolation is a more readable way to format strings, introduced in C# 6.0. It allows you to embed expressions inside string literals using the $ sign.

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string name = "CFD";
int age = 0;
string message = $"My name is {name} and I am {age} years old.";
Console.WriteLine(message); // Outputs: My name is CFD and I am 30 years old.

Verbatim String

A verbatim string literal is prefixed with @ and allows you to include escape sequences like \ as literal characters. It’s useful for file paths and multiline strings.

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string path = @"C:\MyFolder\MyFile.txt";
Console.WriteLine(path); // Outputs: C:\MyFolder\MyFile.txt

string multiline = @"This is a
                   multiline
                   string.";
Console.WriteLine(multiline);
// Outputs:
// This is a
//                    multiline
//                    string.

String Literal

A string literal is prefixed with """ and allows you to write string in mutilple line. It’s useful for multiline strings and complex string interpolation.

• starts with tripple quote then new line and the seperate """ ends

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string multiline = """
This is a
                   multiline
                   string.
""";
Console.WriteLine(multiline); 

• When we want to interpolate some we can do so by prefixing by $ sign and then we can use {} for injection.

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var name = "CFD";
string multiline = $"""
This is a
                   multiline
                   string.
                   {name}
""";
Console.WriteLine(multiline); 

• There may be case when we have to both {} and interpolation the we can do so by prefixing by n number of $ sign and for interpolation we use same number of {} inside string.

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var name = "CFD";
string multiline = $$"""
This is a
                   multiline
                   string.
                   {ignored}
                   {{name}}
                   {{{name}}}
""";
Console.WriteLine(multiline); 

Common String Methods

Replace

Replaces all occurrences of a specified string or character in the original string with another string or character.

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string a = "String";
string b = a.Replace("i", "o");
Console.WriteLine(b); // Outputs: Strong

Insert

Inserts a specified string at a specified index position in the original string.

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string a = "String";
string b = a.Insert(0, "My ");
Console.WriteLine(b); // Outputs: My String

Remove

Removes a specified number of characters from a specified index position in the original string.

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string a = "String";
string b = a.Remove(0, 3);
Console.WriteLine(b); // Outputs: ing

Substring

Retrieves a substring from the original string. The substring starts at a specified index position and has a specified length.

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string a = "String";
string b = a.Substring(0, 3);
Console.WriteLine(b); // Outputs: Str

ToUpper

Converts the string to uppercase.

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string a = "String";
string b = a.ToUpper();
Console.WriteLine(b); // Outputs: STRING

Length

Gets the number of characters in the string.

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string a = "String";
int i = a.Length;
Console.WriteLine(i); // Outputs: 6

Additional Resources

For more detailed information on strings and their manipulation in C#, visit the Official Documentation.

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