Advanced Types in TypeScript
TypeScript provides advanced type features that allow you to create more flexible and reusable code.
Union Types
Union types allow a variable to hold values of multiple types.
let value: string | number;
value = "Hello";
value = 42;
Intersection Types
Intersection types combine multiple types into one.
type Person = { name: string };
type Employee = { id: number };
type EmployeeDetails = Person & Employee;
let employee: EmployeeDetails = { name: "John", id: 123 };
Type Aliases
Type aliases allow you to create custom types.
type StringOrNumber = string | number;
let value: StringOrNumber;
value = "Hello";
value = 42;
Literal Types
Literal types allow you to specify exact values a variable can hold.
let direction: "left" | "right" | "up" | "down";
direction = "left";