Practice 50 Swift Error Handling Programming Questions

Practice 50 Swift Error Handling Programming Questions

Q1. Write a Swift program that defines a function divide(a: Int, b: Int) which throws an error if b is zero and handles the error using a do-catch block.  
Input:  
a = 10, b = 2  
Expected Output:  
Result: 5

Q2. Write a Swift program that defines an enum DivisionError to represent a divide-by-zero error, and uses it in a function that throws an error when division by zero occurs.  
Input:  
a = 15, b = 0  
Expected Output:  
Error: Division by zero

Q3. Write a Swift program to handle an array index out of bounds error by throwing a custom error and handling it using do-catch.  
Input:  
array = [1, 2, 3], index = 5  
Expected Output:  
Error: Index out of bounds

Q4. Write a Swift program that defines a function parseNumber(string: String) which throws an error if the string cannot be converted to an integer.  
Input:  
string = "abc"  
Expected Output:  
Error: Invalid number format

Q5. Write a Swift program to demonstrate the usage of try? when calling a function that might throw an error.  
Input:  
numberString = "abc"  
Expected Output:  
Error: Invalid number format

Q6. Write a Swift program that uses try! to call a function that throws an error, and demonstrates what happens when an error is thrown.  
Input:  
string = "abc"  
Expected Output:  
Fatal error: unexpectedly found nil while unwrapping an Optional value

Q7. Write a Swift program that catches multiple types of errors using a do-catch block.  
Input:  
a = -5, b = 10  
Expected Output:  
Error: Invalid negative value

Q8. Write a Swift program that demonstrates how to throw a custom error in a function and catch it with a do-catch block.  
Input:  
age = -1  
Expected Output:  
Error: Invalid age

Q9. Write a Swift program that defines a function checkPassword(password: String) which throws an error if the password is shorter than 6 characters.  
Input:  
password = "12345"  
Expected Output:  
Error: Password too short

Q10. Write a Swift program that demonstrates how to create a custom error type with associated values and use it for error handling.  
Input:  
username = "john_doe"  
Expected Output:  
Error: Username already taken

Q11. Write a Swift program that demonstrates handling multiple errors in a do-catch block with specific error messages for each case.  
Input:  
value = -3  
Expected Output:  
Error: Value must be positive

Q12. Write a Swift program to demonstrate how to propagate errors from one function to another using throws and try.  
Input:  
a = 10, b = 0  
Expected Output:  
Error: Cannot divide by zero

Q13. Write a Swift program to show the usage of defer to ensure code executes regardless of whether an error occurs or not.  
Input:  
array = [1, 2, 3]  
Expected Output:  
Defer executed

Q14. Write a Swift program that demonstrates how to handle an error with a do-catch block and prints the error description.  
Input:  
number = "abc"  
Expected Output:  
Error: Invalid number format

Q15. Write a Swift program that demonstrates using try? to handle an optional return value and check for error handling.  
Input:  
filePath = "invalid/path"  
Expected Output:  
Error: File not found

Q16. Write a Swift program that defines a function createAccount(username: String) which throws an error if the username already exists.  
Input:  
username = "admin"  
Expected Output:  
Error: Username already taken

Q17. Write a Swift program to handle a custom error in a function that opens a file and throws an error if the file is not found.  
Input:  
filePath = "missing_file.txt"  
Expected Output:  
Error: File not found

Q18. Write a Swift program that throws an error if a string exceeds a certain length and catches the error in a do-catch block.  
Input:  
string = "This is a very long string that exceeds the limit"  
Expected Output:  
Error: String too long

Q19. Write a Swift program to define a function withdraw(amount: Double) which throws an error if the withdrawal amount exceeds the account balance.  
Input:  
balance = 100, withdrawalAmount = 150  
Expected Output:  
Error: Insufficient funds

Q20. Write a Swift program that demonstrates throwing an error inside a closure and handling it outside the closure.  
Input:  
closure = { throw SomeError.someError }  
Expected Output:  
Error: Some error occurred

Q21. Write a Swift program that shows how to use a guard statement for early error handling in a function.  
Input:  
age = -5  
Expected Output:  
Error: Invalid age

Q22. Write a Swift program that demonstrates catching an error thrown by a method inside a class and handling it with do-catch.  
Input:  
amount = -100  
Expected Output:  
Error: Invalid amount

Q23. Write a Swift program that throws an error if the email is invalid and catches the error.  
Input:  
email = "invalidemail.com"  
Expected Output:  
Error: Invalid email address

Q24. Write a Swift program to catch a specific error from a do-catch block and display a custom message.  
Input:  
value = -1  
Expected Output:  
Error: Negative value not allowed

Q25. Write a Swift program that defines a function parseJSON(data: Data) which throws an error if the JSON is malformed.  
Input:  
data = malformed JSON data  
Expected Output:  
Error: JSON parsing failed

Q26. Write a Swift program that demonstrates error handling for invalid user input in a user registration system.  
Input:  
username = "short"  
Expected Output:  
Error: Username too short

Q27. Write a Swift program to handle errors while parsing an integer from a string, using a do-catch block.  
Input:  
string = "abc"  
Expected Output:  
Error: Invalid integer format

Q28. Write a Swift program to handle an invalid file path error using a do-catch block.  
Input:  
filePath = "invalid/path.txt"  
Expected Output:  
Error: File not found at invalid/path.txt

Q29. Write a Swift program that defines an error enum FileError to handle file errors like not found and permission denied.  
Input:  
filePath = "secure/path"  
Expected Output:  
Error: Permission denied

Q30. Write a Swift program that demonstrates the use of try? for error handling and returns nil if the error is thrown.  
Input:  
input = "abc"  
Expected Output:  
Error: Invalid input

Q31. Write a Swift program that demonstrates custom error handling for a network request failure.  
Input:  
requestStatus = "failure"  
Expected Output:  
Error: Network request failed

Q32. Write a Swift program to handle an error while trying to read from a file that doesn't exist.  
Input:  
filePath = "missing_file.txt"  
Expected Output:  
Error: File not found

Q33. Write a Swift program to demonstrate error handling with a do-catch block for a temperature conversion function.  
Input:  
temperature = -500  
Expected Output:  
Error: Invalid temperature value

Q34. Write a Swift program that catches and logs an error thrown from a function and then rethrows the error.  
Input:  
number = -5  
Expected Output:  
Error: Negative number not allowed

Q35. Write a Swift program to handle errors thrown by a method that parses a file and displays an error message if the file is corrupted.  
Input:  
filePath = "corrupted.txt"  
Expected Output:  
Error: File is corrupted

Q36. Write a Swift program that defines a function performOperation(a: Int, b: Int) which throws an error for division by zero.  
Input:  
a = 10, b = 0  
Expected Output:  
Error: Cannot divide by zero

Q37. Write a Swift program to handle a network error thrown when making an API request.  
Input:  
requestStatus = "failure"  
Expected Output:  
Error: Network request failed

Q38. Write a Swift program to throw an error when an input value exceeds the specified limit.  
Input:  
input = 200  
Expected Output:  
Error: Input exceeds limit

Q39. Write a Swift program that throws an error if an invalid age is provided and handles it using do-catch.  
Input:  
age = -1  
Expected Output:  
Error: Invalid age

Q40. Write a Swift program to handle errors while parsing an integer from a string and prints a custom error message.  
Input:  
string = "invalid"  
Expected Output:  
Error: Invalid format

Q41. Write a Swift program to handle errors thrown during JSON decoding with a custom error message.  
Input:  
jsonString = "{\"key\": \"value\"}"  
Expected Output:  
Error: JSON decoding failed

Q42. Write a Swift program to demonstrate error handling while performing a file read operation and handle file not found errors.  
Input:  
filePath = "nonexistent.txt"  
Expected Output:  
Error: File not found

Q43. Write a Swift program to handle division by zero error gracefully by using a custom error type.  
Input:  
a = 10, b = 0  
Expected Output:  
Error: Cannot divide by zero

Q44. Write a Swift program to demonstrate how error handling works when an invalid URL is provided.  
Input:  
url = "invalid://url"  
Expected Output:  
Error: Invalid URL

Q45. Write a Swift program to handle errors when trying to access a dictionary key that does not exist.  
Input:  
dict = ["name": "John"], key = "age"  
Expected Output:  
Error: Key not found

Q46. Write a Swift program that throws an error when trying to add a negative value to a bank account balance.  
Input:  
balance = 100, amount = -50  
Expected Output:  
Error: Cannot add negative balance

Q47. Write a Swift program to handle errors when a user attempts to withdraw more money than their balance allows.  
Input:  
balance = 100, withdrawal = 200  
Expected Output:  
Error: Insufficient funds

Q48. Write a Swift program to handle an error thrown during a network request by printing a custom error message.  
Input:  
requestStatus = "failure"  
Expected Output:  
Error: Network request failed

Q49. Write a Swift program to throw a custom error when an invalid file path is provided, and catch that error in a do-catch block.  
Input:  
filePath = "invalid/path"  
Expected Output:  
Error: Invalid file path

Q50. Write a Swift program to handle a failed attempt to parse a date using a do-catch block and display an appropriate error message.  
Input:  
date = "invalid-date-string"  
Expected Output:  
Error: Invalid date format