Char type and Unicode behavior in C Sharp (C#) - Practice Problems & Coding Challenges

Challenge - 5 Problems

❓ Predict Output

intermediate

Output of char and Unicode code point conversion

What is the output of this C# code snippet?

C Sharp (C#)

char ch = '\u0041';
int code = ch;
Console.WriteLine(code);

A 65

B 41

C A

D Syntax error

💡 Hint

Remember that '\u0041' is a Unicode escape for a character, and casting char to int gives its code point.

The character '\u0041' is 'A'. Its Unicode code point is 65. Casting char to int returns this numeric value.

❓ Predict Output

intermediate

Output of char arithmetic with Unicode characters

What does this C# code print?

C Sharp (C#)

char ch = 'A';
ch = (char)(ch + 2);
Console.WriteLine(ch);

A B

B C

C D

D Runtime error

💡 Hint

Adding 2 to 'A' moves two characters forward in Unicode.

The character 'A' has code 65. Adding 2 gives 67, which is 'C'.

❓ Predict Output

advanced

Output when using surrogate pairs in char arrays

What is the output of this C# code?

C Sharp (C#)

string s = "\U0001F600"; // Unicode emoji 😀
Console.WriteLine(s.Length);

A 2

B 1

C 4

D 0

💡 Hint

Some Unicode characters use two char units called surrogate pairs in .NET strings.

The emoji 😀 is represented by two UTF-16 code units, so Length is 2.

❓ Predict Output

advanced

Behavior of char.IsSurrogate method

What does this C# code print?

C Sharp (C#)

char high = '\uD83D';
char low = '\uDE00';
Console.WriteLine(char.IsSurrogate(high));
Console.WriteLine(char.IsSurrogate(low));

A False\nFalse

B True\nFalse

C True\nTrue

D False\nTrue

💡 Hint

Both high and low surrogate halves are considered surrogate chars.

Both '\uD83D' and '\uDE00' are surrogate code units, so IsSurrogate returns true for both.

🧠 Conceptual

expert

Understanding char and Unicode code points in C#

Which statement about C# char type and Unicode is TRUE?

A The char type can store any Unicode character without needing surrogate pairs.

B A char represents a full Unicode code point, including those outside the Basic Multilingual Plane.

C C# strings store Unicode code points directly as 32-bit integers.

D A char is a 16-bit value representing a UTF-16 code unit, which may be a surrogate half for some characters.

💡 Hint

Think about how UTF-16 encoding works and how C# char relates to it.

C# char is a 16-bit UTF-16 code unit. Characters outside the Basic Multilingual Plane use two chars (surrogate pairs).