Creating instances dynamically in C Sharp (C#) - Performance & Efficiency

Time Complexity: Creating instances dynamically

O(n)

Understanding Time Complexity

When we create objects dynamically in C#, it's important to know how the time it takes grows as we create more objects.

We want to understand how the number of objects affects the total work done by the program.

Scenario Under Consideration

Analyze the time complexity of the following code snippet.

public class MyClass { }

public void CreateObjects(int n) {
    for (int i = 0; i < n; i++) {
        MyClass obj = new MyClass();
    }
}
    

This code creates n new instances of MyClass one after another in a loop.

Identify Repeating Operations

Identify the loops, recursion, array traversals that repeat.

• Primary operation: Creating a new instance of MyClass inside the loop.
• How many times: Exactly n times, once per loop iteration.

How Execution Grows With Input

As n grows, the number of objects created grows the same way.

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

Pattern observation: The work grows directly in proportion to the number of objects created.

Final Time Complexity

Time Complexity: O(n)

This means the time to create objects grows linearly with how many you want to create.

Common Mistake

[X] Wrong: "Creating objects inside a loop is constant time because each creation is fast."

[OK] Correct: Even if one creation is fast, doing it many times adds up, so total time grows with the number of objects.

Interview Connect

Understanding how creating many objects affects time helps you reason about program speed and resource use in real projects.

Self-Check

"What if we create objects inside a nested loop instead of a single loop? How would the time complexity change?"