Parameter properties shorthand in Typescript - Time & Space Complexity

Time Complexity: Parameter properties shorthand

O(n)

Understanding Time Complexity

Let's see how using parameter properties shorthand affects the time it takes to create objects in TypeScript.

We want to know how the work grows when making many objects this way.

Scenario Under Consideration

Analyze the time complexity of the following code snippet.

class Person {
  constructor(public name: string, public age: number) {}
}

const people: Person[] = [];
for (let i = 0; i < n; i++) {
  people.push(new Person(`Name${i}`, i));
}
    

This code creates n Person objects using parameter properties shorthand inside the constructor.

Identify Repeating Operations

• Primary operation: Creating a new Person object inside the loop.
• How many times: The loop runs n times, so object creation happens n times.

How Execution Grows With Input

Each new object takes a small fixed time, and we do this n times.

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

Pattern observation: The work grows directly with n; doubling n doubles the work.

Final Time Complexity

Time Complexity: O(n)

This means the time to create all objects grows in a straight line as you add more objects.

Common Mistake

[X] Wrong: "Using parameter properties shorthand makes object creation faster in a way that changes time complexity."

[OK] Correct: The shorthand just saves typing; the computer still creates each object one by one, so time grows with n.

Interview Connect

Understanding how object creation scales helps you explain code efficiency clearly and confidently in interviews.

Self-Check

"What if we added a nested loop inside the constructor that runs m times? How would the time complexity change?"