07 Arrays in TypeScript

📚 TypeScript Essentials #07 Arrays: Structure, Syntax & Smart Usage

In this episode, we explore one of the most fundamental data structures in TypeScript: the Array. Whether you're storing strings, numbers, or mixed types, arrays give you the flexibility to organize and manipulate data efficiently—with full type safety.

🔍 What You’ll Learn:
- 🧱 Declaring Arrays in TypeScript
→ Using square brackets: let fruits: string[] = ['Apple', 'Banana']
→ Using generic syntax: let ids: Array'number' = [101, 102]
→ Mixed types with union: let values: (string | number)[] = ['A', 1, 'B']
- 🛠️ Accessing & Iterating Over Arrays
→ Index-based access: fruits[0] returns 'Apple'
→ Looping with for, for...in, and for...of
→ Example:
for (let fruit of fruits) {
console.log(fruit);
}
- 🔄 Common Array Methods
→ push(), pop(), shift(), unshift()
→ sort(), concat(), slice(), splice()
→ Example: fruits.push('Mango') adds a new item
- 🔐 Readonly Arrays
→ Prevent mutation with readonly keyword:
const names: readonly string[] = ['Omar']
→ Ensures immutability in shared data structures

- 🧪 Real-World Use Cases
- Storing user roles, product IDs, or form inputs
- Managing dynamic lists in UI components
- Passing typed arrays to functions for validation or transformation

- ⚠️ Best Practices
→ Always define array types for clarity and safety
→ Use union types for mixed content
→ Prefer readonly for constants and config arrays

#typescript #Arrays #TypeSafety #TSBasics #FrontendDev #AutomationTesting #SDET #PlaywrightQA #TypeScriptTutorial #QAEngineering

Видео 07 Arrays in TypeScript канала Omar Elbably