17 OOP - Constructor in TypeScript
🏗️ TypeScript Essentials #17 Constructors: Building Objects with Purpose
In this episode, we explore the role of constructors in TypeScript classes—how they initialize object properties, enforce structure, and support clean, scalable design. Whether you're creating user models, automation components, or service classes, constructors are your gateway to organized, predictable code.
🎯 What You’ll Learn:
🔧 What Is a Constructor?
→ A special method that runs when a class is instantiated
→ Used to initialize properties and set up object state
→ Example:
class User {
name: string;
constructor(name: string) {
this.name = name;
}
}
const user1 = new User('Omar');
🧠 Parameter Properties for Cleaner Code
→ Declare and assign in one step using access modifiers:
class Product {
constructor(public id: number, public name: string) {}
}
🔐 Access Control with public, private, protected
→ Control visibility of constructor parameters and class members
→ Use readonly to lock values after initialization
🔄 Default Values & Optional Parameters
→ Provide flexibility with default values:
constructor(public role: string = 'Viewer') {}
→ Use ? for optional parameters
🧪 Real-World Use Cases
Initializing user profiles, configs, or test data
Injecting dependencies into services or components
Creating reusable automation objects with preloaded state
⚠️ Best Practices & Gotchas
→ Avoid multiple constructor overloads—TypeScript doesn’t support them directly
→ Use type guards or conditional logic inside constructors for flexibility
→ Keep constructors lean—delegate logic to methods when possible
#typescript #Constructor #OOP #TSBasics #FrontendDev #AutomationTesting #SDET #PlaywrightQA #TypeScriptTutorial #QAEngineering