Delegate declaration and instantiation in C Sharp (C#) - Time & Space Complexity

Time Complexity: Delegate declaration and instantiation

O(n)

Understanding Time Complexity

When we declare and create delegates in C#, it's important to know how the time to do this grows as we add more delegates.

We want to understand how the work changes when we create more delegate instances.

Scenario Under Consideration

Analyze the time complexity of the following code snippet.

    delegate void SimpleDelegate();

    void Method() { }

    SimpleDelegate[] delegates = new SimpleDelegate[n];
    for (int i = 0; i < n; i++)
    {
        delegates[i] = new SimpleDelegate(Method);
    }
    

This code creates an array of delegates and fills it by creating a new delegate instance for each element.

Identify Repeating Operations

Identify the loops, recursion, array traversals that repeat.

• Primary operation: Creating a new delegate instance inside a loop.
• How many times: Exactly n times, once for each element in the array.

How Execution Grows With Input

As the number of delegates n increases, the total work grows directly with n.

Input Size (n)	Approx. Operations
10	10 delegate creations
100	100 delegate creations
1000	1000 delegate creations

Pattern observation: The work grows in a straight line as we add more delegates.

Final Time Complexity

Time Complexity: O(n)

This means the time to create all delegates grows directly with the number of delegates you want to create.

Common Mistake

[X] Wrong: "Creating multiple delegates at once is a constant time operation regardless of how many delegates."

[OK] Correct: Each delegate creation takes time, so doing it many times adds up linearly, not instantly.

Interview Connect

Understanding how delegate creation scales helps you reason about event handling and callbacks in real applications, showing you can think about performance even in simple code.

Self-Check

"What if we reused the same delegate instance for all array elements instead of creating new ones? How would the time complexity change?"