String creation and literal types in C Sharp (C#) - Interactive Code Practice

Practice - 5 Tasks

1fill in blank

easy

Complete the code to create a string variable named greeting with the value "Hello".

C Sharp (C#)

string greeting = [1];

Drag options to blanks, or click blank then click option'

A"Hello"

B'Hello'

CHello

Dnew String("Hello")

Attempts:

3 left

💡 Hint

Common Mistakes

Using single quotes instead of double quotes for strings.

Not using quotes at all around the text.

The correct way to create a string literal in C# is by using double quotes. Single quotes are for characters, and unquoted text is invalid. Using new String("Hello") is not valid in C#.

2fill in blank

medium

Complete the code to create a verbatim string literal that includes a file path.

C Sharp (C#)

string path = [1];

Drag options to blanks, or click blank then click option'

A"C:\\Users\\Admin"

B"C:/Users/Admin"

C'C:\Users\Admin'

D@"C:\Users\Admin"

Attempts:

3 left

💡 Hint

Common Mistakes

Using single quotes instead of double quotes.

Not using @ and escaping backslashes manually.

Verbatim string literals in C# start with @ and use double quotes. They treat backslashes as normal characters, so you don't need to escape them.

3fill in blank

hard

Fix the error in the code to correctly create a string with a newline character.

C Sharp (C#)

string message = [1];

Drag options to blanks, or click blank then click option'

A"Hello\nWorld"

B'Hello\nWorld'

C"Hello\World"

D"Hello\rWorld"

Attempts:

3 left

💡 Hint

Common Mistakes

Using single quotes for strings.

Using invalid escape sequences like \W.

In C#, newline characters in strings are represented by \n inside double quotes. Single quotes are for characters, and \World is invalid escape sequence.

4fill in blank

hard

Fill both blanks to create a string that contains a tab character and a double quote inside it.

C Sharp (C#)

string text = [1] + "\t" + [2];

Drag options to blanks, or click blank then click option'

A"Hello"

B'Hello'

C"\"World\""

D'\"World\"'

Attempts:

3 left

💡 Hint

Common Mistakes

Using single quotes for strings.

Not escaping double quotes inside strings.

Strings use double quotes. To include a double quote inside a string, escape it with a backslash \". Single quotes are for characters, so they are incorrect here.

5fill in blank

hard

Fill all three blanks to create a multi-line verbatim string that includes quotes and a newline.

C Sharp (C#)

string poem = [1] + "\n" + [2] + "\n" + [3];

Drag options to blanks, or click blank then click option'

A@"Roses are red,"

B"Violets are blue,"

C@"Sugar is sweet."

D"Sugar is sweet."

Attempts:

3 left

💡 Hint

Common Mistakes

Using single quotes instead of double quotes.

Not using @ for verbatim strings where needed.

Verbatim strings start with @ and use double quotes. You can combine verbatim and normal strings with + and newline characters.

Practice

1. Which of the following correctly creates a string literal in C#?

easy

A. string s = `Hello World`;

B. string s = 'Hello World';

C. string s = Hello World;

D. string s = "Hello World";

Solution

1. Step 1: Understand string literal syntax in C#

   Strings in C# must be enclosed in double quotes (").

2. Step 2: Check each option for correct syntax

   string s = "Hello World"; uses double quotes correctly. string s = 'Hello World'; uses single quotes which are for characters, not strings. string s = Hello World; has no quotes, so it's invalid. string s = `Hello World`; uses backticks which are not valid string delimiters in C#.

3. Final Answer:

   string s = "Hello World"; -> Option D

4. Quick Check:

   Strings use double quotes = A [OK]

Hint: Strings always use double quotes in C# [OK]

Common Mistakes:

• Using single quotes for strings
• Omitting quotes around text
• Using backticks instead of quotes

2. Which of the following is the correct way to create a verbatim string literal in C#?

easy

A. string path = @"C:\Users\Admin";

B. string path = "C:\\Users\\Admin";

C. string path = 'C:\Users\Admin';

D. string path = `C:\Users\Admin`;

Solution

1. Step 1: Recall verbatim string syntax

   Verbatim strings start with @ and use double quotes, preserving backslashes as-is.

2. Step 2: Analyze each option

   string path = "C:\\Users\\Admin"; uses normal string with escaped backslashes. string path = @"C:\Users\Admin"; uses @ with double quotes correctly. string path = 'C:\Users\Admin'; uses single quotes which is invalid for strings. string path = `C:\Users\Admin`; uses backticks which are invalid.

3. Final Answer:

   string path = @"C:\Users\Admin"; -> Option A

4. Quick Check:

   Verbatim strings start with @ = A [OK]

Hint: Use @ before quotes for verbatim strings [OK]

Common Mistakes:

• Forgetting @ for verbatim strings
• Using single quotes for strings
• Not escaping backslashes in normal strings

3. What is the output of the following C# code?

string s = "Line1\nLine2";
Console.WriteLine(s);

medium

A. Line1\nLine2

B. Line1\n\nLine2

C. Line1
Line2

D. Line1 Line2

Solution

1. Step 1: Understand escape sequences in strings

   The sequence \n represents a newline character in C# strings.

2. Step 2: Predict output of Console.WriteLine

   The string "Line1\nLine2" will print as two lines: "Line1" on the first line and "Line2" on the second line.

3. Final Answer:

   Line1 Line2 -> Option C

4. Quick Check:

   \n creates new line = D [OK]

Hint: Escape \n prints new line in output [OK]

Common Mistakes:

• Printing \n literally instead of new line
• Confusing verbatim strings with normal strings
• Expecting spaces instead of new lines

4. Identify the error in this C# string declaration:

string s = @"Hello\nWorld";

medium

A. Escape sequences like \n are not processed in verbatim strings

B. No error, this is correct verbatim string

C. Backslash should be doubled as \\ in verbatim strings

D. Missing semicolon at the end

Solution

1. Step 1: Understand verbatim string behavior

   Verbatim strings treat backslashes literally and do not process escape sequences like \n.

2. Step 2: Analyze the given string

   The string @"Hello\nWorld" will contain the characters \ and n literally, not a newline.

3. Final Answer:

   Escape sequences like \n are not processed in verbatim strings -> Option A

4. Quick Check:

   Verbatim strings ignore escape sequences = B [OK]

Hint: Verbatim strings do not process escape sequences [OK]

Common Mistakes:

• Expecting \n to create new line in verbatim strings
• Doubling backslashes unnecessarily in verbatim strings
• Confusing normal and verbatim string rules

5. You want to create a string that contains the exact text:

C:\Users\Admin\Documents

Which of the following C# declarations will produce this exact string value?

hard

A. string path = "C:\Users\Admin\Documents";

B. string path = @"C:\Users\Admin\Documents";

C. string path = "C:\\Users\\Admin\\Documents";

D. string path = 'C:\Users\Admin\Documents';

Solution

1. Step 1: Understand how to represent backslashes in strings

   In normal strings, backslash is an escape character, so to represent one backslash, you must write \\.

2. Step 2: Check each option for resulting string

   string path = @"C:\Users\Admin\Documents"; uses verbatim string which preserves backslashes literally, producing the exact text with single backslashes. string path = 'C:\Users\Admin\Documents'; uses single quotes which is invalid for strings. string path = "C:\Users\Admin\Documents"; has single backslashes which are escape sequences and will produce the correct path string with single backslashes. string path = "C:\\Users\\Admin\\Documents"; doubles each backslash, resulting in double backslashes in the string, which is not the exact text.

3. Final Answer:

   string path = @"C:\Users\Admin\Documents"; -> Option B

4. Quick Check:

   Verbatim string preserves backslashes literally = D [OK]

Hint: Use verbatim string (@) to preserve backslashes literally [OK]

Common Mistakes:

• Using single quotes for strings
• Doubling backslashes unnecessarily in verbatim strings
• Confusing verbatim and normal string rules