Named arguments in C Sharp (C#) - Interactive Code Practice

Practice - 5 Tasks

1fill in blank

easy

Complete the code to call the method using a named argument for 'age'.

C Sharp (C#)

PrintPersonInfo(name: "Alice", [1]: 30);

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

Ainfo

Bname

Cage

Dperson

Attempts:

3 left

💡 Hint

Common Mistakes

Using the wrong parameter name like 'info' or 'person'.

Forgetting to use the parameter name before the value.

The method expects a named argument 'age' to specify the person's age.

2fill in blank

medium

Complete the method call using named arguments for both parameters.

C Sharp (C#)

DisplayMessage([1]: "Hello", [2]: 5);

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

Atext

Bcount

Cmessage

Dnumber

Attempts:

3 left

💡 Hint

Common Mistakes

Swapping parameter names or using incorrect names.

Omitting parameter names when required.

The method parameters are named 'text' and 'count', so use these names in the call.

3fill in blank

hard

Fix the error by using the correct named argument in the method call.

C Sharp (C#)

CalculateArea(width: 10, [1]: 5);

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

Asize

Bheight

Cdepth

Dlength

Attempts:

3 left

💡 Hint

Common Mistakes

Using 'length' or 'depth' instead of 'height'.

Not matching the parameter names exactly.

The method expects a parameter named 'height' to calculate the area.

4fill in blank

hard

Fill both blanks to call the method with named arguments in any order.

C Sharp (C#)

SetUserDetails([1]: "John", [2]: 25);

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

Aage

Bname

Cusername

Dscore

Attempts:

3 left

💡 Hint

Common Mistakes

Using incorrect parameter names like 'username' or 'score'.

Mixing up the order without using named arguments.

The method parameters are 'name' and 'age'. Named arguments can be in any order.

5fill in blank

hard

Fill all three blanks to call the method with named arguments correctly.

C Sharp (C#)

CreateAccount([1]: "user123", [2]: "pass456", [3]: "[e-mail]");

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

Ausername

Bpassword

Cemail

Daddress

Attempts:

3 left

💡 Hint

Common Mistakes

Using wrong parameter names like 'address'.

Forgetting to use named arguments for clarity.

The method parameters are 'username', 'password', and 'email'. Use these names as named arguments.

Practice

1. What is the main benefit of using named arguments in C#?

easy

A. It makes the program run faster.

B. You can specify which parameter gets which value by name, improving readability.

C. It allows you to skip parameters without default values.

D. It automatically converts data types.

Solution

1. Step 1: Understand named arguments purpose

   Named arguments let you assign values to parameters by their names instead of relying on order.

2. Step 2: Identify the benefit

   This makes code easier to read and understand because you see which value goes to which parameter.

3. Final Answer:

   You can specify which parameter gets which value by name, improving readability. -> Option B

4. Quick Check:

   Named arguments improve readability = A [OK]

Hint: Named arguments improve code clarity by naming parameters [OK]

Common Mistakes:

• Thinking named arguments speed up execution
• Assuming named arguments skip required parameters
• Believing named arguments convert types automatically

2. Which of the following is the correct syntax to call a method PrintInfo with named arguments name and age?

easy

A. PrintInfo(name => "Alice", age => 30);

B. PrintInfo("Alice": name, 30: age);

C. PrintInfo(name = "Alice", age = 30);

D. PrintInfo(name: "Alice", age: 30);

Solution

1. Step 1: Recall named argument syntax

   In C#, named arguments use the format parameterName: value.

2. Step 2: Check each option

   PrintInfo(name: "Alice", age: 30); uses correct syntax. Options A, B, and C use invalid syntax for named arguments.

3. Final Answer:

   PrintInfo(name: "Alice", age: 30); -> Option D

4. Quick Check:

   Named argument syntax = parameterName: value [OK]

Hint: Use colon ':' between parameter and value for named arguments [OK]

Common Mistakes:

• Using '=' instead of ':' for named arguments
• Placing value before parameter name
• Using '=>' instead of ':'

3. What will be the output of the following code?

void ShowDetails(string name, int age) {
    Console.WriteLine($"Name: {name}, Age: {age}");
}

ShowDetails(age: 25, name: "Bob");

medium

A. Compilation error due to argument order

B. Name: 25, Age: Bob

C. Name: Bob, Age: 25

D. Runtime error

Solution

1. Step 1: Understand named argument order flexibility

   Named arguments allow passing parameters in any order by specifying names explicitly.

2. Step 2: Analyze the call

   The call uses age: 25 first and name: "Bob" second, which is valid and assigns correctly.

3. Final Answer:

   Name: Bob, Age: 25 -> Option C

4. Quick Check:

   Named arguments allow any order = C [OK]

Hint: Named arguments can be in any order if names are used [OK]

Common Mistakes:

• Assuming positional order is required with named arguments
• Confusing parameter names and values
• Expecting errors from reversed argument order

4. Identify the error in this method call:

void Display(string title, int count) { }

Display(count: 5, "Hello");

medium

A. Positional argument cannot follow named argument.

B. Missing semicolon after method call.

C. Parameter names are incorrect.

D. No error, code is correct.

Solution

1. Step 1: Recall argument order rules

   In C#, positional arguments must come before any named arguments.

2. Step 2: Analyze the call

   The call uses a named argument count: 5 first, then a positional argument "Hello", which is invalid.

3. Final Answer:

   Positional argument cannot follow named argument. -> Option A

4. Quick Check:

   Positional before named = B [OK]

Hint: Always put positional arguments before named ones [OK]

Common Mistakes:

• Placing positional arguments after named arguments
• Ignoring argument order rules
• Assuming named arguments can be anywhere

5. Given the method:

void Configure(string mode, int timeout = 30, bool verbose = false) { }

Which call correctly uses named arguments to set verbose to true and keep default timeout?

hard

A. Configure("fast", verbose: true);

B. Configure(verbose: true, "fast");

C. Configure(timeout: 30, "fast", verbose: true);

D. Configure("fast", true);

Solution

1. Step 1: Understand default parameters and named arguments

   Default parameters can be skipped if not specified. Named arguments let you set specific parameters by name.

2. Step 2: Analyze each call

   Configure("fast", verbose: true); sets mode positionally and verbose by name, skipping timeout to use default. Configure(verbose: true, "fast"); has positional after named (invalid). Configure(timeout: 30, "fast", verbose: true); mixes positional and named incorrectly. Configure("fast", true); sets verbose positionally, which is wrong type.

3. Final Answer:

   Configure("fast", verbose: true); -> Option A

4. Quick Check:

   Named arguments skip defaults correctly = A [OK]

Hint: Use named arguments to skip default parameters safely [OK]

Common Mistakes:

• Placing positional arguments after named arguments
• Passing wrong types positionally
• Trying to set named arguments before positional ones