There are several reasons to choose TypeScript over JavaScript:
1. Type Safety
TypeScript's biggest advantage is its type system. In TypeScript, you can declare variable types during development, which helps catch type errors early. For example, in JavaScript, if you mistakenly assign a string to a variable that should be a number, this error might only be discovered at runtime. In TypeScript, such errors are caught during compilation, reducing the occurrence of runtime errors.
2. Better Tool Support
Due to TypeScript providing type information, IDEs and other tools can leverage this information for advanced features like autocomplete, navigation, and refactoring. This makes development more efficient, especially when dealing with large codebases. For example, when using TypeScript in VS Code, you can easily find all references to a variable and rename symbols, etc.
3. Better Suited for Large Projects
JavaScript is very flexible, but this flexibility can become a burden in large projects. TypeScript's strong type system helps standardize the codebase, making it easier to manage and maintain. Additionally, TypeScript supports advanced object-oriented programming features such as interfaces and abstract classes, which help build more structured and scalable code.
4. Community and Ecosystem Support
TypeScript is maintained by Microsoft, with strong community support and a growing ecosystem. Many popular libraries and frameworks (such as Angular, React) provide TypeScript type definitions, making it easier and safer to develop with TypeScript.
5. Progressive Adoption
TypeScript is a superset of JavaScript, meaning any valid JavaScript code is valid TypeScript code. This allows existing JavaScript projects to be progressively migrated to TypeScript without rewriting existing code.
Example
In my previous project, we migrated from JavaScript to TypeScript. Initially, we frequently encountered runtime errors related to types, which were often difficult to debug. After migrating to TypeScript, we could catch most type errors during compilation, significantly improving development efficiency and reducing bug rates in production.
Overall, although TypeScript introduces a type system and a compilation step, which may increase learning and development costs, its advantages in improving code quality, enhancing development tool functionality, and better maintaining large codebases are evident. These features make TypeScript a preferred choice for many enterprises and development teams.