typescript

Key Features

• Static Typing: Enforces type checking at compile time to catch errors early.

• Code Completion: Enhances IDE support for better autocompletion and suggestions.

• Refactoring: Simplifies code restructuring with type safety.

• Shorthand Notations: Provides concise syntax for common patterns.

Overview

TypeScript (TS) is a superset of JavaScript (JS) that adds discipline to make code more robust and maintainable. It builds on JS, meaning all valid JS code is also valid TS code.

Drawbacks

• Transpilation: TS code must be compiled to JS, adding a build step.

• Discipline: Requires stricter coding practices, which may slow initial development.

Debugging in VSCode

To debug TypeScript in VSCode: Open the Debug Panel. 2. Click Create a launch.json file and select Node.js. 3. Add the following rule to launch.json:

"preLaunchTask": "tsc: build - tsconfig"

Data Types

JavaScript Types

• number

• string

• boolean

• null

• undefined

• object

TypeScript-Specific Types

• any: Allows any type, bypassing type checking.

• unknown: Safer alternative to any, requires type checking before use.

• never: Represents values that never occur (e.g., a function that always throws).

• enum: Defines a set of named constants.

• tuple: Arrays with fixed length and specific types for each element.

Best Practices

Configure tsconfig.json with the following for cleaner, safer code:

• "noUnusedLocals": true – Flags unused variables to keep code tidy.

• "noUnusedParameters": true – Ensures all function parameters are used, preventing mistakes.

• "noImplicitReturns": true – Requires explicit return types for all code paths in functions.