JavaScript vs TypeScript: Key Differences

JavaScript	TypeScript
Dynamically typed: Types are determined when the code runs.	Statically typed: Types are checked before the code runs, during the compile-time.
No type checking, which can lead to errors only discovered when the code is running.	Type checking is done in advance, preventing many errors before running the code.
Limited support for modern development tools.	Provides better integration with modern tools, such as autocomplete and real-time error detection, in editors like VSCode.
No interfaces or type aliases.	Supports interfaces (defines the structure or shape of an object, e.g., an object must have 'name' and 'age' properties) and type aliases (gives a custom name to a type, e.g., 'UserType' can represent an object with specific properties).
No abstract classes.	Supports abstract classes (provides a blueprint for other classes and prevents direct instantiation; ensures child classes implement specific methods).
Basic object-oriented programming support.	Enhanced object-oriented programming (OOP) features, such as access modifiers (control who can use a class property or method: 'public' means accessible to all, 'private' means accessible only within the class, and 'protected' means accessible within the class and its subclasses), abstract classes, and interfaces.
Refactoring can be risky because there's no automatic type checking to catch errors.	Safer refactoring is possible due to static typing, which helps identify type-related issues during code changes.
Errors usually show up only when the code is running, which can lead to unexpected problems.	Errors are detected earlier (during compilation), preventing issues before running the code.
Example: let name = 'John'; name = 123; (No error until runtime)	Example: let name: string = 'John'; name = 123; (Compilation error: Type 'number' is not assignable to type 'string')