Mastering TypeScript: Unleashing the Power of Advanced Types for Flexible Code

As we continue our journey into TypeScript mastery, it’s time to explore the advanced type features that set TypeScript apart from traditional JavaScript. These features provide a higher level of flexibility and expressiveness in your code.

1. Union and Intersection Types:

• Union Types:
• Union types allow a variable to have multiple types. For example, a variable can be a string or a number. let userID: string | number; userID = "abc123"; userID = 456;
• Intersection Types:
• Intersection types combine multiple types into one. This is useful when you want an object to have characteristics of several types. interface Employee { id: number; role: string; } interface Manager { department: string; } type ManagerEmployee = Employee & Manager; const managerEmployee: ManagerEmployee = { id: 1, role: "Supervisor", department: "IT", };

2. Generics:

Generics provide a way to create flexible and reusable components. They allow you to write functions and classes without specifying the exact types, leaving that to the caller.

// A simple generic function
function identity<T>(arg: T): T {
  return arg;
}

const resultString: string = identity("Hello, TypeScript!");
const resultNumber: number = identity(42);

3. Conditional Types:

Conditional types enable you to create types that depend on other types. They introduce a level of logic to your type declarations.

type CheckUser<T> = T extends { isAdmin: true } ? "Admin" : "Regular User";

const userA: CheckUser<{ isAdmin: true }> = "Admin"; // Valid
const userB: CheckUser<{ isAdmin: false }> = "Regular User"; // Valid

Understanding and utilizing these advanced type features will empower you to write more flexible and sophisticated TypeScript code. In the next part, we’ll explore working with classes and objects in TypeScript, delving into the principles of object-oriented programming. Stay tuned for a deep dive into TypeScript’s object-oriented capabilities!