TypeScript

TypeScript adds static types to JavaScript. Errors appear during development instead of production. The type system provides predictability for large applications and enables AI-assisted code generation.

Immediate Error Detection

TypeScript catches mistakes while writing code:

// TypeScript shows error immediately
function processOrder(order: Order): number {
  return order.items.reduce((total, item) => total + item.price, 0);
}
processOrder(null); // Editor highlights error

The compiler prevents type mismatches from reaching users. Runtime crashes become compile-time warnings.

Self-Documenting Interfaces

Types document code structure automatically:

interface User {
  id: string;
  email: string;
  subscription: 'free' | 'pro' | 'enterprise';
}

async function upgradeUser(userId: string, plan: 'pro' | 'enterprise'): Promise<User> {
  // Implementation
}

Function signatures explain parameters and return values. Interfaces describe data shapes. Documentation stays synchronized with code.

Bug Prevention

TypeScript eliminates entire categories of JavaScript errors:

• Null reference crashes
• Undefined property access
• Wrong argument types
• Unhandled error cases

These bugs disappear at compile time rather than crashing production applications.

Runtime Integration

TypeScript works with runtime validation libraries:

import { z } from 'zod';

const UserSchema = z.object({
  email: z.string().email(),
  age: z.number().min(18)
});

type User = z.infer<typeof UserSchema>;

One schema provides compile-time types and runtime checks. External data gets validated while internal code maintains type safety.

Related Documentation

Additional Resources