17 Apr, 2024 | Mobile App Development
TypeScript vs JavaScript: Which One is Better to Choose?
Introduction
TypeScript and JavaScript are two of the most popular programming languages for building client-side applications on the web. Both share syntax similarities but differ in fundamental aspects, like static vs. dynamic typing. JavaScript has been around since 1995 and is natively supported in all modern browsers. It is an essential part of the web and powers client-side logic through scripts. Its dynamic nature allows flexibility but lacks compiler checks. TypeScript was developed by Microsoft in 2010 as a typed superset of JavaScript, adding static typing and tooling support while still compiling to plain JavaScript. It aims to apply rigorous checking during development for fewer bugs. Since then, TypeScript has grown rapidly due to its promise of enhanced developer productivity and code quality. However, a pure replacement of JavaScript is not feasible given its ubiquity. This has led to diverse opinions on whether to choose TypeScript or JavaScript for a new project. This blog analyzes the core differences between TypeScript and JavaScript regarding their type systems, tooling, performance, and ecosystem to help understand their strengths and whether one is a better choice in different scenarios. It also addresses common questions developers face when deciding which language to adopt.
What is TypeScript?
TypeScript is an open-source programming language developed and maintained by Microsoft. It is a strict syntactical superset of JavaScript and primarily adds optional static typing to the language. This helps catch errors early and allows leveraging modern tooling. Today, 55,944+ websites are using this effective language worldwide. TypeScript compilation outputs plain JavaScript code, allowing it to run directly in any web browser or JavaScript runtime environment. It builds on JavaScript syntax and provides features like classes, interfaces, typed variables, and error checking during compilation. This superior type-safety and IntelliSense capabilities aid in managing large codebases. The codebases are also highly scalable and reusable. Its static analysis at compile time means programmers can build robust apps with more maintainable code. With increased adoption by enterprises, TypeScript promises longevity and acts as the safe evolution of JavaScript. It has secured its place in the industry with continued enhancements.What is JavaScript?
JavaScript is a lightweight, cross-platform, and interpreted scripting language best known as the scripting language for Web pages. It was spearheaded by Netscape in 1995 and has since become essential for adding interactivity to Web pages. JavaScript can update dynamic HTML/XML content, control program flow, and handle events. It has made front-end development easier by enabling dynamic content reloading without reloading the web page. JS also forms the basis of frontend frameworks like AngularJS and ReactJS for enhanced productivity. JavaScript is used by 98.7% (or 49,501.698 websites) of the websites worldwide. While JS excels at enabling interactive UIs and websites, its weakly typed and loosely structured nature initially made codebases hard to scale. However, features like classes, modules, and type-checking have advanced it significantly. Still evolving rapidly with improvements, JS remains the primary language for browser-based scripting.Core differences between TypeScript and JavaScript
Now, we are in the post's primary section, where we will emphasize "Typescript vs JavaScript” in terms of different aspects. Let’s start!1. Static Typing
Static typing refers to a type system where the data type is known at compile time rather than run time. This means the compiler can validate and ensure the code uses the expected types correctly. Differences between TypeScript and Javascript according to Static Typing- Catch errors early: Static type checking during compilation catches errors related to types, like passing wrongly typed parameters to functions. This helps fix issues early.
- Auto-complete: Editor suggestions are available based on static types, improving developer productivity.
- Refactoring: Refactoring code is safer as the compiler catches any introduced type errors.
- Documentation: Types provide documentation for parameters/return values useful during collaboration.
- No type-checking was done during compilation. Code is only checked at runtime.
- No errors were caught during the writing/editing of code related to types. Only surfaces during execution.
- No auto-complete suggestions related to types in code editors.
- Refactoring carries the risk of introducing hidden type bugs not caught until runtime.
- Missing documentation for functions regarding expected/return types.
2. Compile-time Checks
TypeScript code is compiled to JavaScript, allowing static analysis that catches errors before runtime. This improves productivity by fixing bugs sooner. Features like refactoring are also safer in TypeScript. JavaScript, on the other hand, does not have this compile-time safety net. Differences between TypeScript and Javascript according to Compile-time Checks- TypeScript code is first compiled into JavaScript code.
- During compilation, the type checker validates types across the codebase.
- Any type errors, missing imports, etc, are reported at compile time before runtime.
- Catches errors early before running code
- Fix and prevent bugs before they occur at runtime
- Enables refactoring safely by catching issues during compile
- Improves code quality by validating correct usage of types
- JavaScript code executes directly without the compilation step
- No type checking or validation of code done beforehand
- Errors related to types only occur and are reported at runtime
- No guarantee code is bug-free before executing
3. Interfaces
Interfaces in TypeScript define contracts for objects and functions to implement. This allows for describing relationships between various components. Interfaces promote code reuse through strong abstraction and decoupling of types from implementations. This aids in developing robust and maintainable apps over JavaScript's looser implicit typing. Differences between TypeScript and Javascript according to Interfaces- Enforce contracts between classes/functions
- Self-documenting code with interfaces
- Strict type-checking for objects
- Aids refactoring by catching failures to adhere to shape
- No way to define custom value shapes that classes/functions can adhere to
- Missing type safety between functions/classes interacting with each other
- Harder to understand expected object properties from code
- Difficult refactoring if changing class structure
4. Object-Oriented Programming
OOP refers to programming using objects and related concepts like abstraction, encapsulation, polymorphism, and inheritance. It allows the modeling of real-world entities as objects that interact by passing messages. Below are the features that we are going to assess in context to the comparison of TypeScript and JavaScript:- Classes - Classes are blueprints for objects that define their properties and behaviors. They support inheritance and polymorphism.
- Encapsulation - It is the bundling of data with the methods that operate on that data. Encapsulation prevents data from direct modification.
- Inheritance - It allows the creation of new classes that reuse and inherit properties and behaviors of existing classes.
- Interfaces - Interfaces define common behaviors/actions but leave implementation to classes. It allows polymorphism.
- Abstraction - It focuses on important attributes hiding unnecessary details behind class/interface definitions.
- Polymorphism - It means multiple forms and allows one interface with multiple implementations through inheritance.
- Supports OOP concepts like classes, inheritance, and abstraction, allowing object-oriented modeling
- Encapsulates state and behaviors within classes
- Interfaces define common shapes for multiple classes
- Inheritance allows code reuse through class extension
- Prototypal inheritance instead of classes
- No access modifiers like private
- Object models built via prototypes lack abstraction and structure
- Functions mimic classes but miss OOP structure
5. Development Tools and IDE Support
Development tools refer to compilers, linters, editors, debuggers, etc, that improve developer productivity and code quality. Below are the attributes that differentiate both TypeScript and JavaScript. Check it out:- Auto Complete - It intelligently suggests properties and methods as code is typed based on static type analysis.
- Refactoring Support - Refactoring is supported through rename/extract methods etc without breaking existing code.
- Linting & Errors - Linting performs static analysis to find stylistic/structural errors, while errors highlight issues.
- Debugging - Debugging tools allow stepping through code, inspecting scope, accessing variable values etc.
- Code Navigation - It allows quickly navigating to references, traversing hierarchical imports, file structures etc.
- Autocomplete speeds up coding based on expected types
- Refactoring safety via compilation checking for breaking changes
- Bugs caught during editing via linting rather than runtime
- Seamless debugging experience with source maps
6. Application Performance
Performance refers to how fast an application executes and responds and efficient memory usage. Here are a few app performance features that differentiate TypeScript and JavaScript.- Type Check Overhead - Type checking during compilation increases bundle size and initialization time.
- Bundle Size - Larger bundles require more bandwidth for loading applications.
- Initialization - Initialization is the loading and execution of code during app startup.
- Runtime - Runtime is the time taken for code execution after app initialization and loading.
7. Backward Compatibility
Backward compatibility refers to the ability of newer versions of software to work with older versions. Below are the features of Backward Compatibility that showcase the difference between TypeScript and JavaScript:- Compilation Target - Older JS versions for wider browser coverage without the latest JS features.
- JavaScript Compatibility - Maintains compatibility while adding new language features.
- Browser Support - Needs compilation for older browser support while JS runs directly.
- Features Parity - Maintains language structure and semantics comparable to JavaScript.
8. Modern JavaScript Support
Keeping pace with the latest advances in JavaScript language and ecosystem, we have identified 3 features to compare TypeScript and Javascript. Here are these 3 features:- Latest ECMAScript: A standard programming language used for client-side scripting on the World Wide Web.
- Types Checking: A feature that checks your program is correctly coded before execution. There are 2 types of Type checking - Static and Dynamic.
- Transpiling for Older Browsers: A feature to convert a language’s source code into an equivalent version of the same or different programming language.
9. Learning Curve
It means the amount of initial effort that is required to learn the language. Below we discuss differences of the same in terms of TypeScript and JavaScript. Check out the Learning Curve differences for TypeScript vs JavaScript:10. Maturity and Adoption
When it comes to maturity and adoption, it is considered to be different phases or stages of development and community support levels. Below, we discuss different parameters of development stages that differentiate TypeScript and JavaScript. Check out the Maturity differences in TypeScript vs. JavaScript:Should I learn JavaScript or TypeScript?
TypeScript builds on JavaScript syntax and adds optional static types, interfaces, and class features. Learning TypeScript is better for new projects because of its robust type safety and compiler checks, which reduce bugs. However, JS still has excellent browser support and compatibility. Overall, it is better to learn both for a full-stack career.Will TypeScript Replace JavaScript?
Considering JavaScript's dominance in web development, it is unlikely TypeScript will fully replace it. However, TypeScript is projected to become the mainstream language of choice for new complex web applications due to its strong typing, compiler capabilities and being a superset of JavaScript. It ensures safer and more maintainable apps at scale. JavaScript will still be required for runtime compatibility but TypeScript will eventually overtake JS for new large projects for its advantages.Final Verdict
So, TypeScript combines the debugging and catch-errors-early benefits of static typing with JavaScript's flexibility to significantly improve the development experience without major trade-offs in comprehension, compatibility, or performance. For new applications, libraries, and frameworks, TypeScript is generally the best choice to write high-quality code while leveraging modern IDE features and tooling. While JavaScript will remain relevant, TypeScript hits an excellent balance of type safety with approachability, making it the future-proof option. Make your choice wisely!
Frequently Asked Questions
1. Is it ideal to learn TypeScript or JavaScript?
If you are just starting out, it's better to learn JavaScript first to understand core programming concepts. TypeScript builds on JavaScript, so learning JavaScript provides a strong foundation. However, TypeScript isn't vastly more difficult - so it can also be learned directly, especially if wanting to work with types from the beginning.
2. Is Typescript better than JavaScript?
It's generally not recommended to replace an existing JavaScript codebase with TypeScript outright. TypeScript is highly compatible with JavaScript, so both can co-exist with TypeScript code being able to use JavaScript libraries and vice versa. New projects are better started with TypeScript while existing codebases can migrate incrementally.
3. What is more in common, JS or TS?
JavaScript is by far the most popular and widely used language currently based on usage statistics. However, TypeScript adoption is growing rapidly among new projects for its type safety and tooling benefits. Both have enormous communities and long-term prospects, so popularity depends on the use case and requirements.
4. Which is more relevant for React, JavaScript, or TypeScript?
TypeScript is a smarter choice for React projects because it supports static types across React components and libraries. Although plain JavaScript works, too, TypeScript allows type-checking interactions between React components, propTypes, and states for fewer bugs. It also safely enables refactoring React apps and improves developer experience through rich editor features. In summary, while JavaScript will continue to dominate due to its ubiquity, TypeScript has established itself as the preferred choice for new projects. It prioritizes developer productivity, stability, and performance through its strong static typing system. Both languages can coexist depending on an application's specific needs.
Written by Pratik
Pratik is a co-founder of WEDOWEBAPPS LLC. He has been at the forefront of the business, expanding it globally with the latest technologies. He also has a passion for sharing his expertise with clients and other enthusiasts. He usually writes based on Technology, Leadership, and Entrepreneurship.
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