C# Character Variable Type

C#'s char type is aliasing the System.Char type. It represents a Unicode character and occupies 2 bytes.

When we talk about characters we are referring to individual letters and numbers. For example, the letter 'a' is a character, as is the visual representation of the number '1'. Such characters may be stored in a C# char variable. A char variable can contain one character and one character only.

A char literal is specified inside single quotes (‘’): char c = 'A';

For character data types we can specify literals in three ways:

• Single quote
• Unicode Representation
• Escape Sequence

Single quote

We can specify literal to char data type as single character within single quote.

char ch = 'a';

Unicode Representation

We can specify char literals in Unicode representation ‘\uxxxx’. Here xxxx represents 4 hexadecimal numbers.

char ch = '\u0061';// Here /u0061 represent a.

Escape Sequence

Every escape character can be specified as char literals.

Escape sequences express characters that cannot be expressed literally.

An escape sequence is a backslash followed by a character with a special meaning.

For example:

char newLine = '\n';
char backSlash = '\\';

The escape sequence characters are shown in the following table.

\u (or \x) escape sequence specify Unicode character using four-digit hexadecimal code:

char copyrightSymbol = '\u00A9';
char omegaSymbol     = '\u03A9';
char newLine         = '\u000A';

Example C# Char (Character Literals)

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;

namespace HelloWorld
{
    class Program
    {
        static void Main(string[] args)
        {
            // character literal within single quote
            char ch = 'a';

            // Unicode representation
            char c = '\u0061';

            Console.WriteLine(ch);
            Console.WriteLine(c);

            // Escape character literal
            Console.WriteLine("Hello World\nFrom XDevSpace\t!");
            Console.ReadLine();
        }
    }
}

Output:

Note that there is a special character sequence for the Backslash (\\). Because the special characters begin with a backslash the compiler interprets any instances of a single backslash as the pre-cursor to a special character. This raises the question of what to do if you really want a backslash. The answer is to use the double backslash special constant sequence.

C# System.Char Type

System.Char defines a range of static methods for working with characters.

For example, You can use ToUpper to convert a char to its upper case.

You can call these through either the System.Char type or its char alias:

Example:

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;

namespace HelloWorld
{
    class Program
    {
        static void Main(string[] args)
        {
            Console.WriteLine(System.Char.ToUpper('c'));    // C
            Console.WriteLine(char.IsWhiteSpace('\t'));     // True
            Console.ReadLine();
        }
    }
}

Output:

ToUpper and ToLower honor the end user's locale.

System.Char and System.String provides culture-invariant versions of ToUpper and ToLower ending with the word Invariant.

These always apply English culture rules:

Console.WriteLine (char.ToUpperInvariant ('i'));    //I

This is a shortcut for:

Console.WriteLine (char.ToUpper ('i', CultureInfo.InvariantCulture))

The following table lists static methods related to categorizing characters:

C# Char Conversions

An implicit conversion from a char to a numeric type works for the numeric types that can accommodate an unsigned short.

For other numeric types, an explicit conversion is required.