TypeScript Tips for Better Code Quality

TypeScript adds static typing to JavaScript, helping you catch errors early and write more maintainable code. Here are essential tips to improve your TypeScript skills.

## 1. Use Type Inference

Let TypeScript infer types when possible:

```typescript
// Good - Type is inferred
const message = "Hello, World!"

// Unnecessary - Explicit type not needed
const message: string = "Hello, World!"
```

## 2. Leverage Union Types

Union types allow a value to be one of several types:

```typescript
type Status = 'pending' | 'success' | 'error'

function handleStatus(status: Status) {
// TypeScript knows status can only be one of three values
}
```

## 3. Use Interfaces for Objects

Define object shapes with interfaces:

```typescript
interface User {
id: number
name: string
email: string
}

function greetUser(user: User) {
console.log(`Hello, ${user.name}!`)
}
```

## 4. Enable Strict Mode

Always use strict mode in your tsconfig.json:

```json
{
"compilerOptions": {
"strict": true
}
}
```

## 5. Use Utility Types

TypeScript provides helpful utility types:

```typescript
// Partial - Make all properties optional
type PartialUser = Partial

// Pick - Select specific properties
type UserPreview = Pick

// Omit - Exclude specific properties
type UserWithoutEmail = Omit
```

## 6. Generic Functions

Write reusable code with generics:

```typescript
function getFirstElement(arr: T[]): T | undefined {
return arr[0]
}

const firstNumber = getFirstElement([1, 2, 3]) // Type: number
const firstString = getFirstElement(['a', 'b']) // Type: string
```

## Best Practices

1. **Don't use `any`** - It defeats the purpose of TypeScript
2. **Use `unknown` instead of `any`** - When you truly don't know the type
3. **Leverage type guards** - Narrow types safely
4. **Document complex types** - Use JSDoc comments

## Conclusion

TypeScript significantly improves code quality and developer experience. These tips will help you write better, more maintainable TypeScript code.