Multicast delegates in C Sharp (C#) - Interactive Code Practice

Practice - 5 Tasks

1fill in blank

easy

Complete the code to declare a delegate named MyDelegate.

C Sharp (C#)

public delegate void [1]();

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AMyDelegate

BAction

CDelegate

DFunc

Attempts:

3 left

💡 Hint

Common Mistakes

Using built-in delegate types like Action or Func instead of declaring a new delegate.

Using an invalid delegate name.

The delegate is declared with the name MyDelegate to match the usage later.

2fill in blank

medium

Complete the code to add method1 to the multicast delegate.

C Sharp (C#)

MyDelegate d = method1; d [1]= method2;

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A*=

B+

C+=

D-=

Attempts:

3 left

💡 Hint

Common Mistakes

Using + instead of +=.

Using -= which removes a method.

The += operator adds a method to the invocation list of the multicast delegate.

3fill in blank

hard

Fix the error in the code to invoke the multicast delegate safely.

C Sharp (C#)

if ([1] != null) d();

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Amethod1

Bd

CMyDelegate

Ddelegate

Attempts:

3 left

💡 Hint

Common Mistakes

Checking a method name instead of the delegate variable.

Not checking for null before invoking.

Before invoking a delegate, check if the delegate variable d is not null to avoid exceptions.

4fill in blank

hard

Fill both blanks to remove method2 from the multicast delegate and invoke it.

C Sharp (C#)

d [1]= method2; if (d [2] null) d();

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A-=

B!=

C==

D+=

Attempts:

3 left

💡 Hint

Common Mistakes

Using += instead of -= to remove a method.

Checking d == null instead of d != null.

Use -= to remove a method from the delegate. Then check if d != null before invoking.

5fill in blank

hard

Fill all three blanks to create a multicast delegate, add two methods, and invoke it safely.

C Sharp (C#)

MyDelegate d = method1; d [1]= method2; if (d [2] null) d[3]();

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

A+=

B!=

C()

D;

Attempts:

3 left

💡 Hint

Common Mistakes

Forgetting to add methods with +=.

Not checking for null before invoking.

Missing parentheses when calling the delegate.

Use += to add methods, check d != null before invoking, and call the delegate with ().