📚 TypeScript Data Types

As discussed earlier, JavaScript is a loosely typed language because it does not require explicitly defining data types for variables.
However, that doesn’t mean JavaScript lacks data types — it definitely has them!

The key difference between JavaScript and TypeScript is:

• In JavaScript, types are handled internally (automatic typecasting).
• In TypeScript, you can explicitly define a data type — and TypeScript enforces it (though defining types is optional).

TypeScript offers a powerful and flexible type system. Here’s how it classifies data types:

🎯 The Any Type

• The any type is the super type of all types in TypeScript.
• When you use any, you tell the compiler not to perform any type checking on that variable.
• It gives flexibility but removes type safety.

Example:

let data: any = 5;
data = "Hello World";
data = true;

🛠 Built-in Types

TypeScript provides several built-in data types:

⚡ Note: There is no separate “integer” type in TypeScript or JavaScript — everything numeric is of type number.

🤔 Null and Undefined — Are They the Same?

Short answer: ❌ No, they are not the same!

• Undefined: A variable that has been declared but not assigned any value automatically gets undefined.
• Null: A variable explicitly assigned null indicates a deliberate non-value or “empty” object reference.

Both represent “absence” of value, but they serve different purposes in programming.

🏗 User-defined Data Types

TypeScript not only supports built-in types but also provides user-defined types to build complex applications:

• 🧩 Enumerations (enums)
• 🏛 Classes
• 🧾 Interfaces
• 📦 Arrays
• 🎯 Tuples

These allow developers to structure their code in a clear, scalable, and object-oriented way.