Objects & Interfaces
Defining Objects in TypeScript
Objects in TypeScript are collections of key-value pairs with explicitly defined structures using type annotations.
- Objects must conform to the defined structure, ensuring all required properties are present.
- Additional properties not specified in the type definition will result in an error.
- TypeScript enforces correctness at compile time, reducing runtime errors.
// Object with explicit type annotation
let person: { name: string; age: number } = {
name: "Jake",
age: 25
};
// Missing or extra properties cause errors
let invalidPerson = { name: "Jake" }; // Error: Property 'age' is missing
let extraProperty = { name: "Jake", age: 25, city: "Sydney" }; // Error: Extra property 'city'