TryParse for safe conversion in C Sharp (C#) - Practice Problems & Coding Challenges

Challenge - 5 Problems

❓ Predict Output

intermediate

Output of TryParse with valid integer string

What is the output of this C# code snippet?

C Sharp (C#)

string input = "123";
bool success = int.TryParse(input, out int result);
Console.WriteLine($"Success: {success}, Result: {result}");

A Success: False, Result: 0

B Success: True, Result: 0

C Success: True, Result: 123

D Compilation error

💡 Hint

TryParse returns true if conversion succeeds and sets the out parameter.

The string "123" is a valid integer, so TryParse returns true and sets result to 123.

❓ Predict Output

intermediate

TryParse with invalid integer string

What will this C# code print?

C Sharp (C#)

string input = "abc";
bool success = int.TryParse(input, out int result);
Console.WriteLine($"Success: {success}, Result: {result}");

A Success: False, Result: 0

B Success: True, Result: 0

C Runtime exception

D Success: False, Result: -1

💡 Hint

TryParse returns false if conversion fails and sets result to zero.

The string "abc" cannot be converted to int, so TryParse returns false and result is 0.

🧠 Conceptual

advanced

Why use TryParse instead of Parse?

Which statement best explains why TryParse is safer than Parse for converting strings to numbers?

A TryParse automatically converts any string to zero if it fails.

B Parse returns a boolean but does not output the converted value.

C Parse is faster and safer than TryParse.

D TryParse returns a boolean indicating success and does not throw exceptions on failure.

💡 Hint

Think about error handling and exceptions.

TryParse returns true or false to indicate success and avoids exceptions, making it safer for user input.

❓ Predict Output

advanced

TryParse with double and culture settings

What is the output of this C# code?

C Sharp (C#)

string input = "3.14";
bool success = double.TryParse(input, System.Globalization.NumberStyles.Any, System.Globalization.CultureInfo.InvariantCulture, out double result);
Console.WriteLine($"Success: {success}, Result: {result}");

A Success: False, Result: 0

B Success: True, Result: 3.14

C Success: True, Result: 314

D Compilation error

💡 Hint

InvariantCulture uses dot as decimal separator.

The string "3.14" matches the InvariantCulture format, so TryParse succeeds and result is 3.14.

❓ Predict Output

expert

TryParse with nullable int and conditional operator

What is the output of this C# code?

C Sharp (C#)

string input = "42";
int? number = int.TryParse(input, out int temp) ? temp : (int?)null;
Console.WriteLine(number.HasValue ? number.Value.ToString() : "No value");

A 42

B No value

C Compilation error

D 0

💡 Hint

TryParse returns true and temp gets the parsed value.

TryParse succeeds, so number is assigned temp (42), and output is "42".