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Système de Types
TypeScript Syntax Guide
Annotations de type et système de types TypeScript
Système de Types
Annotations de type et système de types TypeScript
TypeScript système de types (typescript)
// Basic types
let name: string = "John";
let age: number = 25;
let isActive: boolean = true;
let data: any = "anything";
let unknown: unknown = "mystery";
// Arrays and tuples
let numbers: number[] = [1, 2, 3];
let tuple: [string, number] = ["hello", 42];
// Union types
let mixed: string | number = "hello";
mixed = 42; // OK
// Type aliases
type UserId = string | number;
type Point = {
x: number;
y: number;
};
// Interfaces
interface User {
id: UserId;
name: string;
email?: string; // Optional property
readonly createdAt: Date; // Read-only property
}
// Interface extending
interface Admin extends User {
permissions: string[];
}
// Generic interface
interface ApiResponse<T> {
data: T;
status: number;
message?: string;
}
// Usage
const user: User = {
id: 1,
name: "John",
createdAt: new Date()
};
const admin: Admin = {
id: "admin123",
name: "Admin",
createdAt: new Date(),
permissions: ["read", "write", "delete"]
};
const response: ApiResponse<User[]> = {
data: [user],
status: 200
};
Explanation
TypeScript ajoute la frappe statique à JavaScript avec des annotations de type. Il prend en charge les types primitifs, les types complexes, les génériques et les interfaces pour une meilleure fiabilité du code.
Common Use Cases
- Sécurité des types
- Meilleur support IDE
- Documentation
- Confiance dans le refactoring
Related TypeScript Syntax
Master Système de Types in TypeScript
Understanding Système de Types is fundamental to writing clean and efficient TypeScript code. This comprehensive guide provides you with practical examples and detailed explanations to help you master this important concept.
Whether you're a beginner learning the basics or an experienced developer looking to refresh your knowledge, our examples cover real-world scenarios and best practices for using Système de Types effectively in your TypeScript projects.
Key Takeaways
- Sécurité des types
- Meilleur support IDE
- Documentation